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Immunization practice is complicated,
and getting more complicated every year.
New vaccines, such as rotavirus
and human papillomavirus are introduced and need
to be integrated into the schedule.
Recommendations are changed for existing vaccines,
as recently occurred
for meningococcal conjugate and TDAP vaccines.
It is easy to get confused.
We have found that a discussion of the general principles
of vaccination, and broad recommendations for the use
of vaccines can help reduce confusion.
So we will spend most of this session discussing these general
principles and recommendations.
We will then apply the general principles to specific vaccines
in subsequent sessions.
Any discussion of immunization should begin
with a discussion of immunology.
We do not intend to go into much detail,
but we will give you enough to get the general idea.
Let's start off with a consideration of immunity.
What is it exactly?
In the broadest sense, immunity is our ability
to recognize self from non-self.
That is, the immune system is able to recognize
and eliminate foreign, or non-self material,
from the body, and leave everything
that belongs there alone.
But for the purposes of this program,
we will use a narrower concept of immunity.
You can think of immunity as protection
from infectious disease, the ability to recognize
and eliminate infectious agents, such as viruses and bacteria,
and to prevent infection with these agents in the future.
There are two basic types of immunity, active and passive.
It is possible for both types to be present simultaneously.
We will discuss both types of immunity,
starting with active immunity.
Active immunity is the best type,
because it is protection produced
by a person's own immune system.
Active immunity is usually permanent,
and provides long lasting protection against re-infection
with that virus or bacterium.
A good model for active immunity is that which occurs
after an infectious disease.
In most cases, lifelong immunity results
if a person survives an infectious disease.
Second infections- at least symptomatic infections-
are not common in an immune person.
Here is a short animation to illustrate the process
of active immunity from infection.
The first event leading to immunity is exposure
of a susceptible person to an infectious agent,
in this case, a virus.
Because the person is not immune, the virus is able
to replicate and spreads throughout the body.
As the viruses spread, some are captured
by special antigen presenting cells, such as B cells.
The B cell engulfs the virus, disassembles it
into smaller parts, and presents some
of the viral parts on its surface.
The viral antigens presented
by the B cell attract another key cell of the immune system -
a T cell, shown here in yellow.
The T cell controls many functions of the immune system.
It sends chemical signals to activate the B cell.
Each activated B cell then begins to divide.
This process is known as clonal expansion
because each daughter B cell is a clone,
identical to the original activated cell.
Many of these millions of activated B cells will transform
into plasma cells and begin
to produce protein molecules called antibodies.
Antibodies attach to the invading virus,
interfere with its ability to produce more viruses,
and facilitate destruction of the virus
by other cells of the immune system.
The combined forces of the antibodies and other components
of the immune system eliminate the invading virus from the body
and confer active immunity.
The antibodies, and some of the activated B cells,
called memory cells,
remain after the virus has been eliminated,
making the person immune to that virus.
Active immunity can result either from infection
with the disease-causing form of the organism
or through vaccination, and will persist for years,
probably for the life of the person.
The entire process from infection to elimination
of virus usually takes one to two weeks,
but it can take longer, depending on the organism.
Months or years later, another exposure to the virus may occur.
The circulating antibodies will recognize the virus,
and memory cells will rapidly produce more antibody.
Because of the antibody and other components
of the immune system, the virus will be unable
to replicate enough to cause disease.
The exposed person is usually unaware
that the exposure even occurred.
What was illustrated in that animation is generically known
as an immune response.
There are two central elements in this immune response
to infection- antigen and antibody.
Antigen is a live or inactivated substance, such as a protein
or polysaccharide, which is capable
of producing an immune response.
The antigen in the animation was the invading virus.
Antibodies are the muscle of the immune response.
Antibodies are protein molecules,
known as immunoglobulins, produced by B lymphocytes
in response to the antigen.
Antibodies assist other components of the immune system
in the elimination of an antigen.
Antibodies are very specific, and only recognize the antigen
which produced them, or very closely related antigens.
The immune system is complex.
There are other components
which help control invasion by infectious agents.
There is another important arm of the immune system known
as cell mediated immunity,
which involves activated T lymphocytes or killer cells.
But for simplicity we will equate the presence of antibody
with a person being immune, or protected from that disease.
There are exceptions to this, such as pertussis,
which we discuss
in the pertussis segment of this series.
So antibodies are great things to have around.
It is preferable to actively produce the antibodies yourself,
but it is not the only way to get them.
It is possible to get them, ready-made,
from another person or animal.
The transfer of antibody from one person
to another is known as passive immunity.
The antibodies still do what they are supposed to do-
recognize and help eliminate antigen.
This type of immunity is usually effective, at least for a while.
The problem is that passive immunity is not permanent
and wanes with time.
Here is a short animation
that illustrates the process of passive immunity.
One type of immunity is passive immunity.
With passive immunity, a person receives antibodies
from another person rather than producing them.
The most common type of passive immunity occurs
when a fetus receives its mother's antibodies
across the placenta.
A full-term infant is born with antibodies
against the same diseases to which the mother is immune.
As the infant grows,
the maternally acquired antibodies circulate
through the body.
Since the infant did not actively produce the antibodies,
the level declines with time.
If the infant is exposed to a disease
for which it has maternally-acquired antibodies,
the antibodies will recognize and help
to eliminate the invading organism, just as it would
if the infant were immune from infection.
One potential problem with passive immunity is
that the maternally-acquired antibodies cannot tell the
difference between disease-causing virus
and live vaccine virus.
So, if the infant receives a live virus vaccine while
maternal antibodies are still circulating,
the antibodies will recognize the vaccine virus
and help eliminate it from the body,
preventing active immunity from occurring.
By the time the infant is about a year old,
all maternal antibodies will have disappeared.
Now the infant is susceptible to infection
with either the disease-causing or vaccine form of the organism.
Because there are no circulating antibodies to interfere,
live vaccines given
to the infant will confer active immunity.
Maternally acquired immunity is only one type
of passive immunity.
Injection with immune globulin or disease-specific globulin,
or transfusion of blood products are other ways
of conferring passive immunity.
But passive immunity, no matter how acquired,
is always temporary.
Active immunity, either from infection
with the disease-causing form of the organism
or through vaccination, is the only way
to become permanently immune to disease.
Passive immunity is defined as protection in the
form of antibody transferred from an exogenous source,
usually another person.
Transplacental antibody is a very important source
of passive immunity.
Maternal antibody is actively transported across the placenta
in the last six to eight weeks of pregnancy.
So a full term infant is born
with the same antibodies that the mother has.
The problem is that if the mother is not immune
to a disease, the infant will not be immune,
and is susceptible to infection from the moment of birth.
Passive antibody transfer happens
in other ways, of course.
Some antibody is passively transferred
with blood transfusions, for example.
There are three chief medical sources of passive antibody.
The first is homologous- meaning same species-
pooled human antibody, commonly known as immune globulin.
Those little vials of immune globulin contain antibody
from the blood of hundreds of American adult donors.
Immune globulin is used for hepatitis A
and measles postexposure prophylaxis,
among other indications.
Immune globulin derived
from American donors will contain antibodies
to these viruses.
In contrast, immune globulin from the U.S. would have little
or no antibody to yellow fever,
since relatively few North Americans are exposed
to this disease or vaccinated against it.
A second antibody product is homologous human
hyperimmune globulin.
These products have a high concentration of antibody
to a specific disease.
For instance hepatitis B immune globulin, HBIG, which is used
for postexposure prophylaxis, is taken from donors
with high levels of hepatitis B antibody.
HBIG will contain a large amount of hepatitis B antibody,
but also smaller amounts of antibodies to other antigens,
like measles and hepatitis A. Hyperimmune globulin products
are also available for postexposure prophylaxis
of tetanus, varicella, and rabies.
Vaccinia immune globulin is used
to treat certain adverse reactions following
smallpox vaccine.
There is also an antibody product available
for the prevention of infection
with respiratory syncytial virus- or RSV- in infants.
There has been a lot of confusion about this product.
Although it is used to PREVENT RSV infection, and administered
by intramuscular injection, it contains only ANTIBODY.
It is not a vaccine.
The product is palivizumab, or Synagis.
Synagis is unique because it is monoclonal- it is produced
in a special way so that it contains ONLY RSV antibody.
It does not contain antibody to any other antigen.
We will discuss the implications of this a little later
when we talk about antibody vaccine interactions.
A third antibody product is heterologous-
meaning different species- hyperimmune serum,
also known as antitoxin.
Antitoxin is different because it is produced
in horses, not humans.
Equine antitoxin is used in the United States for treatment
of diphtheria, botulism, and some snake bites.
The problem with equine antitoxin is
that the immune system may identify the horse protein
as not self and develop an immune response to it.
This could result in a condition known as serum sickness.
We will come back to passive immunity later in this program
because the presence
of passively acquired antibody may reduce the effectiveness
of some injected live virus vaccines.
Let's talk next about how vaccines produce
active immunity.
You will recall that active immunity is induced by infection
with the disease causing form of viruses and bacteria.
With vaccines, we attempt to simulate that process,
but without actually producing the disease,
and without producing the complications
that may accompany the disease.
At present there are two basic types of vaccines -
live attenuated vaccines, which must replicate inside the body
in order to be effective, and inactivated vaccines,
which cannot replicate.
There are subtypes of both.
Among live attenuated vaccines, live viral vaccines predominate.
There are two live bacterial vaccines,
but these are not commonly used
in the U.S. There are two main groups of inactivated vaccines,
those that contain inactivated whole viruses or bacteria,
and a large second group, which we will refer
to as fractional vaccines.
These vaccines contain only fragments
of the organism of interest.
Among the fractional vaccines, most are protein- based,
such as subunit vaccines and toxoids.
Some fractional vaccines are polysaccharide- based,
and may be either pure polysaccharide
or conjugate polysaccharide.
In order to simplify some of the principles of vaccination,
we have developed a few general rules.
Here is the first General Rule: The more similar a vaccine is
to the disease- causing form of the organism,
the better the immune response to the vaccine.
This makes sense, since disease induced immunity is generally
long lasting, and the closer we can approximate
that with vaccine, the better the protection from the vaccine.
From this rule you would expect
that live vaccines would have some advantages,
since infectious diseases are caused by live organisms.
To illustrate how live vaccines work,
here is our third animation.
The events that produce immunity
with a live attenuated vaccine are almost identical to those
which lead to immunity following infection
with the disease-causing form of the organism.
The two main differences are that exposure is intentional,
usually through injection of the virus,
and that the virus is attenuated or weakened,
so it does not to cause illness.
Since the person is not immune, the vaccine virus is able
to replicate, and spreads throughout the body.
The vaccine virus is very similar to natural disease virus
so the immune system cannot tell them apart.
B cells and other antigen-presenting cells engulf
and disassemble the virus
and present viral antigens on their surface.
The viral antigens are recognized
by a T cell, shown here in yellow.
The T cell signals the B cell to activate.
The activated B cells begin to divide, producing millions
of identical daughter B cells.
Many of these B cells transform into plasma cells
and then produce antibodies directed
against the vaccine virus.
As with infection with the disease-causing form
of the virus, the antibody attaches to the vaccine virus
and facilitates its destruction
by other components of the immune system.
This leads to elimination of the virus from the body.
The antibody and memory B cells produced in response
to the vaccine virus infection will persist for many years
after the vaccine virus has been eliminated.
Because the antibodies cannot distinguish
between vaccine virus and disease virus,
the person is now immune, probably for life, to infection
with a disease-causing form of the organism.
So if months or years later an exposure
to disease virus occurs,
the antibodies will recognize the virus
and facilitate its elimination
by other components of the immune system.
No disease will result from the exposure.
As you can see, the immune response
to a live vaccine is very similar to active immunity
that results from infection
with the disease-causing form of the organism.
In both situations, the infectious organism replicates
until an immune response is generated,
which eliminates the invading pathogen.
We will be mostly talking about live VIRUS vaccines,
since we rarely use live bacterial vaccines
in the United States.
Live vaccines are an attenuated, or weakened,
form of the wild viruses or bacteria.
WILD is a jargon term for the form of the virus or bacterium
which causes the disease.
For example, the measles vaccine
that is used today originally caused measles DISEASE
in a child in 1954.
It took 9 years to transform the wild measles virus
into the vaccine virus that is used now.
Live vaccines must replicate to be effective
and to produce an immune response.
That is how they work.
Anything that interferes with replication can decrease
or eliminate the vaccine's ability to produce immunity.
The immune response to a live vaccine is very similar
to the immune response
that occurs following natural illness, or infection
with the disease-causing form of the organism.
The mechanism is the same in both cases: the viruses
or bacteria replicate until an immune response stops the
organisms from replicating and eliminates them from the body.
As a result, live vaccines produce immunity
in most recipients with one dose.
However, a small percentage of recipients do not respond
to the first dose of an injected live vaccine,
such as MMR or varicella.
So a second dose is recommended to provide a very high level
of immunity in the population.
Typically live oral vaccines require more doses
than injected live vaccines.
Because they replicate, severe reactions are possible
if the immune system cannot eliminate the vaccine organism.
Fortunately, these severe reactions are rare,
and occur mainly when live vaccines are erroneously
administered to immunosuppressed persons.
An important limitation of some live vaccines,
particularly measles vaccine, is interference
from circulating antibody.
Antibody against the vaccine virus can reduce
or eliminate the ability of the live vaccine agent to replicate.
And if live vaccines do not replicate they do not work.
Interference by circulating antibody appears
to be a problem mainly with injected live virus vaccines.
Finally, live vaccines are relatively fragile.
They must be stored and handled very carefully or risk reducing
or destroying their potency.
We use several live attenuated vaccines in the United States.
Here is a list of them.
The live viral vaccines are measles, mumps, and rubella,
which are given as combined MMR vaccine; varicella and zoster,
which contain the same vaccine virus but in different amounts;
yellow fever; live attenuated influenza; rotavirus;
and vaccinia, or smallpox vaccine.
Oral polio is a live virus vaccine
but is not currently available in the United States.
There are two live bacterial vaccines -BCG and oral typhoid.
BCG vaccine is used for the prevention of tuberculosis.
BCG is one of the most commonly used vaccines in the world.
Most of you will never administer a dose
of BCG vaccine, since it is not available in the United States.
But most clinicians have seen the results of BCG vaccination
on the arms of children and adults from other countries.
This image shows two circular BCG scars on the arm
of a woman from El Salvador.
These scars are sometimes confused
with those caused by smallpox vaccine.
The second major vaccine category is inactivated vaccine.
The antigen in inactivated vaccine is not alive,
but it interacts with the immune system
in a way similar to live vaccines.
To illustrate how inactivated vaccines work,
we would like to show you our last animation.
The events which produce immunity
to inactivated vaccine are similar to those leading
to immunity following infection with the disease-causing form
of the organism or vaccination with live attenuated vaccine.
The person is injected with inactivated antigen,
which can be a whole inactivated virus, or fragments
of a killed virus or bacterium.
Since the antigen is dead, it cannot reproduce.
So larger quantities
of inactivated vaccine antigen must be injected
to stimulate an immune response.
As with infection or vaccination with live vaccines,
the inactivated antigen is captured and ingested by B cells
and other antigen-presenting cells.
The B cell processes the antigen and presents it on its surface.
These antigens are recognized by a T cell.
The T cell signals the B cell to activate.
The B cells divide, just as they do after infection
with the disease causing form of the organism or after receipt
of live attenuated vaccine.
Many will transform into plasma cells
and then produce antibody directed
against the vaccine antigen.
Antibodies attach to the vaccine antigen,
leading to its elimination from the body.
Unlike infection with the disease-causing form
of the organism or vaccination with live vaccines,
a single dose of inactivated vaccine may not confer immunity.
Only a small amount of antibody is produced,
and it may disappear quickly.
Additional doses may be needed to boost the immune response.
A second dose of antigen, usually given
within a few months of the first causes a similar response.
More antibody is produced, which attaches to the vaccine antigen
and facilitates its elimination
by other components of the immune system.
This time, more antibodies remain
but long-lasting immunity still may not be conferred.
One or more additional doses may be required
to increase the antibodies to a protective level.
But even this protection can gradually decline over time.
An additional booster dose may be needed years
after the primary series to ensure
that the antibody level remains protective.
While antibodies remain in body, the person is immune
to the disease-causing form of the virus or bacterium.
If an exposure to the disease organism occurs,
the antibodies will recognize and help to eliminate it.
Usually there is no illness from the exposure.
Illness may occur, but it is usually less severe
than in an unvaccinated person.
The basic immune response process is similar
with both live and inactivated vaccines.
The main difference is that live antigens replicate
until the immune system stops them.
Inactivated agents cannot replicate,
so the immune system must usually be exposed
to the antigen several times in order to produce immunity.
Here are some other characteristics
of inactivated vaccines.
Inactivated vaccines are not alive, so they cannot replicate
and are noninfectious.
Because they are noninfectious, they can be administered
to an immunosuppressed person.
In general, inactivated vaccines are not as effective
as live attenuated vaccines, meaning that estimates
of vaccine efficacy are usually lower than with live vaccines.
One way that circulating antibody helps
to eliminate infectious agents is to interfere
with their replication.
Since inactivated vaccines do not replicate,
there is less interference from circulating antibody
than for live vaccines.
This means you can give inactivated vaccines
in the presence of passive antibody,
such as maternal antibody,
so you can give them earlier in life.
In fact, it is common to give inactivated vaccine
and antibody at the same time.
For instance, an infant born to a woman with acute
or chronic hepatitis B virus infection receives hepatitis B
immune globulin in one leg
and hepatitis B vaccine in the other leg.
The same thing happens for postexposure rabies prophylaxis.
Another difference between live and inactivated vaccines is
that live vaccines produce immunity
in most recipients with a single dose.
Inactivated vaccines generally require 3 to 5 doses.
The first dose usually does not provide much protection.
It is a primer for the immune system.
The subsequent 2 or 3 doses provide protection
by increasing antibody levels.
The immune response
to an inactivated vaccine is mostly humoral,
unlike live vaccines which produce both humoral
and cellular immunity.
Unlike live vaccines, in which immunity is generally long
lasting, the antibody titer following an inactivated vaccine
may diminish with time, and may
in some cases fall below a protective level.
It is not known why live vaccines produce
such good long term immunologic memory,
and some inactivated vaccines do not.
When antibody wanes to a non protective level,
it may be necessary to give the immune system a little reminder,
in the form of a booster dose of vaccine.
Tetanus and diphtheria toxoids
and meningococcal conjugate vaccines are examples
of vaccines that require booster doses
to maintain protection in healthy people.
Inactivated whole virus vaccines available
in the U.S. include inactivated polio, rabies,
and hepatitis A vaccines.
Inactivated whole cell bacterial vaccines, such as cholera
and whole cell pertussis vaccine are available in some countries,
but none are available in the United States.
Here is a list of fractional vaccines,
which contain only parts of a virus or bacterium.
Subunit vaccines include hepatitis B, influenza,
acellular pertussis, human papillomavirus, and anthrax.
There are two toxoids, which are inactivated toxins
of diphtheria and tetanus.
Acellular pertussis vaccines could be classified
as toxoids as well.
We discuss pertussis vaccines in the third module of the course.
Yabo?
Another type of fractional vaccine is composed
of polysaccharide, either alone
or conjugated to a protein carrier.
Polysaccharides are complex sugars that make
up the outer coat of certain bacteria,
most notably the Streptococcus, Neisseria,
and Haemophilus families.
The polysaccharide coat is important in the development
of disease and immunity.
So vaccine production should be fairly straightforward.
Just purify the polysaccharide and put it in a vial.
That is one way to make a polysaccharide vaccine,
but there is a catch.
Most polysaccharides are T independent antigens.
You will recall from the animations
that the T cell is very important
in the development of immunity.
Polysaccharides are capable of stimulating the B cell directly,
without the help of a T cell.
This may seem like a good thing, but it is not.
Polysaccharides are not very potent antigens.
Most importantly, polysaccharide vaccines are not consistently
immunogenic in children younger than two years of age.
This is a serious shortcoming if the disease you want
to prevent occurs commonly in infants, like Hib
and pneumococcal disease.
In addition to this lack of effect in infants,
polysaccharide vaccines do not reliably produce a
booster response.
That means that the amount
of antibody produced does not increase substantially following
subsequent doses.
This is the reason the recommendations
for revaccination with pneumococcal
and meningococcal polysaccharide vaccines are a bit vague.
Repeated doses result in little or no additional protection.
Another limitation of polysaccharide vaccines is
that they produce antibody with less functional activity.
Much of the antibody produced is IgM, instead of IgG.
The good news is that the limitations
of pure polysaccharide vaccines can be remedied.
The immunogenicity of these vaccines is improved
by conjugation, literally a joining
of polysaccharide with protein.
The resulting conjugated material is a T-dependent
antigen, and does not have the limitations
of a T-independent antigen.
Most importantly, conjugates are effective in infants.
We now have six polysaccharide-based vaccines.
Pure polysaccharide vaccines, which are only administered
to persons 2 years and older, include pneumococcal,
meningococcal, and typhoid Vi vaccines.
Conjugate polysaccharide vaccines include Haemophilus
influenzae type b, pneumococcal
and meningococcal conjugate vaccines.
Unlike Hib and pneumococcal conjugate,
meningococcal conjugate vaccine is not routinely recommended
for infants in the United States.
So, in summary, there are two basic types of immunity.
Active immunity is produced by a person's own immune system
and is often life-long.
Active immunity is produced by vaccination.
Passive immunity is effective but is always temporary.
There are also two basic types of vaccine- those
that contain live attenuated organisms and those
that contain inactivated organisms,
or only parts of an organism.
The age of vaccination and schedule
for most vaccines varies depending on type.
We discuss specific information for each vaccine
in other segments of this series.
Immunization schedules are an integral part
of immunization practice.
Because immunization recommendations change
frequently, the schedules
for the United States are revised annually.
The schedule for children and adolescents birth
through age 18 years, and for adults 19 years
and older are issued separately.
Both sets of schedules are published in Morbidity
and Mortality Weekly Report, or MMWR, in January
or February of each year.
The development
of the immunization schedules is a collaborative effort.
The schedules for children and adolescents birth
through 18 years are developed by the three principle groups
that make pediatric immunization recommendations
in the United States.
These groups are the Advisory Committee
on Immunization Practices or ACIP; the American Academy
of Pediatrics; and the American Academy of Family Physicians.
The schedule represents the concurrence of all three groups
for vaccination of children and adolescents.
The ACIP is a group of 15 nongovernmental experts
in public health, infectious diseases, and clinical medicine.
They are appointed to ACIP by the Secretary of the Department
of Health and Human Services and serve 4 year terms.
The ACIP advises the Centers for Disease Control and Prevention
and the Department of Health and Human Services
on immunization policy.
It is these recommendations
that we will mainly discuss during this program.
Creation of the immunization schedules is a complicated,
year-long process that requires input from ACIP as well
as members of the academies of Pediatrics
and Family Physicians, and others.
The childhood and adolescent schedules must be revised
and approved by ACIP no later than October of each year
in order to be published in January or February
of the following year.
Here is the 2012 schedule for children birth
through 6 years of age.
This schedule was published in Morbidity
and Mortality Weekly Report on February 10, 2012.
Vaccines are listed in rows down the left side,
and ages are indicated in columns across the top.
Vaccine names are listed
under the recommended age for each dose.
Yellow bars that span ages indicate a range
in the recommended age for that dose.
The purple bars indicate vaccines
that are not routinely indicated for ALL children
but are recommended for children in certain high-risk groups.
For 2012 a yellow and purple hashed bar was added
for hepatitis A to reflect a unique recommendation
for vaccination of older children.
The annual immunization schedules are intended
to be a concise summary of current ACIP recommendations.
It is often very challenging
to condense complex immunization recommendations
into just a few sentences.
There were several significant changes made
to ACIP recommendations during 2011, and these are reflected
on the 2012 schedules.
The bar in the meningococcal row
and the meningococcal footnote has been revised
to reflect licensure of one
of the meningococcal conjugate vaccines for infants.
The yellow and purple hashed bar added
to the hepatitis A row helps clarify the recommendation
for completion of the routine schedule,
and for certain children in high risk groups 2 years
of age or older.
Guidance is also now provided for use of measles, mumps,
and rubella, or MMR vaccine in certain infants 6
through 11 months of age.
This recommendation is important for infants 12 months of age
or younger who travel outside the United States.
The footnotes for influenza vaccine have also been revised
to reflect current recommendations
for revaccination of certain children younger
than 9 years of age.
For many years the recommended immunizations for all children
through 18 years of age were included on a single schedule.
But those were simpler times,
when there were fewer vaccines recommended for older children.
There is not enough space on a single schedule
to include recommendations for TDAP, meningococcal conjugate
and HPV vaccines at 11 or 12 years of age.
As a result, since 2007, children 7 through 18 years
of age have had their own schedule.
This is the schedule for children 7
through 18 years of age.
It is laid out like the schedule for younger children with ages
across the top and vaccines in the rows.
Yellow bars indicate the age range
for routinely recommended vaccines.
Purple bars indicate vaccines recommended for persons
in this age group with certain high risk conditions.
This schedule also has green bars to indicate catch
up vaccination - that is,
vaccines that should be administered at this age
if they were NOT administered earlier.
For 2012 the bars have been updated to include the number
of doses required for each vaccine.
Other changes in the schedule for 7
through 18 year old children include the recommendation
for routine use of quadrivalent human papillomavirus vaccine
in males, at 11 to 12 years of age.
Also, the recommendation for a routine booster dose
of meningococcal conjugate vaccine at 16 years
of age has been added to the figure and to the footnote.
Another helpful feature of the child
and adolescent schedules is the catch up immunization schedule.
The catch up schedule will help you accelerate the schedule
for children who start late or who are more
than one month behind.
The top part of the schedule is for children 4 months
through 6 years and the bottom part is for those 7
through 18 years of age.
The lower halves of all three schedules contain footnotes.
The footnotes provide important details about the schedule
such as minimum intervals and ages.
You should ALWAYS read the footnotes carefully.
And you should read the footnotes on each new edition
of the schedules because footnote content changes often.
Most importantly, for the first time,
vaccination providers are being advised
to use all three schedules- birth through 6 years,
7 through 18 years, and the catch-up schedules- as well
as their respective footnotes TOGETHER and not separately.
An attempt has been made to reduce redundancy
between schedules, and between the figures and footnotes.
So all three schedule footnotes should be reviewed to assure
that clinicians obtain all the information needed
to appropriately vaccinate a child.
Childhood vaccination schedules have existed for decades,
and have been revised annually since 1995.
Adults have always needed vaccines as well,
but the first immunization schedule for adults 19 years
and older was not developed until 2002.
Like the childhood schedule,
the adult schedule is revised annually and published
in January or February each year.
The adult immunization schedule is a collaborative effort
of the ACIP, the American Academy of Family Physicians,
the American College of Obstetricians and Gynecologists,
and the American College of Physicians.
The schedule is officially endorsed by each organization.
Here is the adult schedule for 2012.
It is laid out similarly to the childhood schedule
with age groups in the columns and vaccines listed on the left.
The color coding is also similar to the childhood schedule.
Yellow bars indicate vaccines recommended for all persons
in that age group who do not have evidence of immunity.
Purple bars indicate vaccines recommended for persons
with other risk factors that put them
at increased risk for that disease.
A new yellow and purple hashed bar was added for Td
and Tdap vaccines to highlight recommendations
for adults 65 years and older.
The adult schedule includes a second table
that you will find very useful.
Most adult vaccine recommendations are driven
by a risk condition rather than age.
This table lists a variety of conditions, or indications,
in the columns such as pregnancy, immunosuppression,
*** infection, asplenia, and others.
Vaccines are listed on the left.
Yellow bars indicate vaccines the person should receive
if the condition or indication is present.
Unique to this table, red bars indicate a condition
when a particular vaccine is contraindicated
and should NOT be given, such as MMR
and varicella vaccine during pregnancy.
For 2012 a new feature has been added
to the adult immunization schedule.
A table listing contraindications
and precautions for vaccines recommended
for adult is now included.
This table will be revised annually as needed.
Important changes in the 2012 adult immunization schedule
include: the use of TDAP vaccine in pregnancy; recommendations
for use of quadrivalent human papillomavirus, or HPV4 vaccine
for males through 26 years of age; and a recommendation
for hepatitis B vaccination of certain adults with diabetes.
We will discuss these recommendations,
as well as the schedule for specific vaccines
in subsequent sessions of this program.
Please get a copy of the schedules and have them handy
as you view this program.
And be sure to read all the footnotes.
In this segment of the program we will discuss the General
Recommendations on Immunization.
The title refers to immunization recommendations that apply
to more than one vaccine or group of vaccines.
But the title also refers to a specific publication
of the Advisory Committee on Immunization Practices, or ACIP.
Most ACIP statements address a single vaccine
or vaccination issue.
The General Recommendations
on Immunization is unique among ACIP statements
because it provides guidance on vaccination issues common
to more than one vaccine.
The General Recommendations
on Immunization is revised every 3 to 5 years.
The current version was published in January 2011,
and is the most comprehensive version to date.
The General Recommendations include information
on the timing and spacing of vaccines; contraindications
and precautions; preventing and reporting adverse events,
vaccine administration, vaccine storage and handling,
and altered immunocompetence.
There are also sections discussing special vaccination
situations including persons with allergy
to vaccine components, vaccination of preterm infants,
pregnant and breastfeeding women,
internationally adopted children,
hematopoietic cell transplant recipients, and much more.
We would like to discuss three issues
from the General Recommendations that relate to the spacing
and timing of vaccines.
The three interval issues we are going to discuss are the timing
of antibody containing blood products and live vaccines,
simultaneous and nonsimultaneous administration
of different vaccines, and the interval
between subsequent doses of the same vaccine.
These issues come up frequently in vaccination practice
and we get many questions about them.
Let's begin with a general rule.
Inactivated vaccines are generally not affected
by circulating antibody to the antigen.
As a result, inactivated vaccines can be given any time
before or after antibody has been given, or in infancy
when maternal antibody is still present.
Live attenuated vaccines -
primarily INJECTED live attenuated vaccines -
may be affected by circulating antibody to the antigen.
The presence of circulating antibody may affect the age
at which a vaccine is given,
because of persistent maternal antibody.
It may also influence the length of the interval
between administration of an antibody containing product,
such as a blood transfusion, and a vaccine dose.
The interval between antibody and vaccine is most important
for measles, and probably varicella.
Mumps, rubella and rotavirus vaccines seem
to be less sensitive to circulating antibody.
Yellow fever and oral typhoid are not affected
because most blood products
in the United States do not contain a substantial amount
of yellow fever or typhoid antibody.
Live attenuated influenza vaccine
and zoster vaccine do not appear to be affected
by circulating antibody.
If a measles-
or varicella-containing vaccine is administered BEFORE the
antibody containing product,
an interval of at least 2 weeks should separate them.
This interval allows the vaccine virus time to replicate
and produce an immune response before encountering
the antibody.
If the ANTIBODY containing product is given first,
the interval between it and measles-
or varicella-containing vaccine should be 3 months
or longer depending on the antibody product and dose
that was administered.
On the occasions when you encounter this situation,
it would be useful to have a table
that indicates the recommended interval
between the antibody product and the vaccine.
There is a table of these intervals
in the General Recommendations.
This is an image of it.
The table is also available on the updates
and resources web page, and in the course text.
It will be helpful if you get a copy of the table from one
of these sources and follow along this next part
of the discussion.
You can see the table has three columns.
The first column lists most
of the antibody products available in the United States.
The second column is the recommended dose
for that particular product and indication.
The third column lists the interval between receipt
of that product and measles
or varicella vaccine administration.
Let's look at three examples.
The second line is labeled hepatitis A IG.
The second column gives the dose of immune globulin recommended
for contact prophylaxis, and for international travel.
The third column shows the suggested interval before
vaccination with measles
or varicella containing vaccine is 3 months
for either a contact prophylaxis dose
or a dose used before international travel.
This means that in 3 months the dose
of antibody should have waned enough to allow replication
of measles and varicella vaccine virus.
Near the middle of the page,
below blood transfusion is the listing for whole blood.
The recommended interval between a transfusion of whole blood
and measles or varicella vaccine is 6 months.
Near the bottom of the table are 5 rows
for intravenous immune globulin, or IGIV,
for various indications, such as the treatment
of immune thrombocytopenic purpura and Kawasaki disease.
Because of the amount of antibody present in IGIV,
8 to 11 month intervals are recommended
between its administration and live virus vaccination.
You should be aware that some children with *** infection are
on routine IGIV schedules, so you may need to check this table
for intervals before administration
of MMR or varicella vaccine.
The table also includes an entry for an antibody product
for the prevention of RSV.
The product is Synagis.
It is located on the bottom row of the table.
Synagis, whose generic name is palivizumab,
contains monoclonal antibody only to RSV,
and does not contain ANY other antibody.
So Synagis does not interfere with live virus vaccination,
because it does not contain measles, mumps, rubella,
or varicella antibody.
The interval between Synagis and live virus vaccines is ZERO.
Live virus vaccines can be administered any time before
or after administration of Synagis.
Also note that the intervals on this table do NOT apply
to zoster, rotavirus or live attenuated influenza vaccines.
Circulating antibody is not believed to interfere
with replication of these live virus vaccines.
We strongly recommend that you use the intervals in this table
if your patient has received some type of blood product
and needs MMR or varicella vaccine.
If MMR or varicella vaccine is given at an interval SHORTER
than those in the table,
you should either repeat the vaccine dose at a later time,
or use a laboratory test to verify
that there has been a response to the vaccine.
Administering a second dose is probably the easiest
and cheapest course of action.
Do not memorize the antibody table.
But you should copy it, laminate it, post it, and explain it
to other members of your staff- whatever it takes
so everyone knows how to use it and where to find it.
Donna? We will now discuss the simultaneous
and nonsimultaneous administration of vaccines.
The next general rule of vaccination is one
that we will mention often during this program.
All vaccines can be administered at the same visit
as all other vaccines.
Let me repeat that: all vaccines used
in the United States can be administered at the same visit
as all other vaccines.
The simultaneous administration of vaccines is critical
to raising and maintaining high immunization levels.
Simultaneous administration neither decreases vaccine
efficacy nor increases the risk of adverse reactions.
It does NOT overload the immune system which is very capable
of coping with many antigens every day.
Simultaneous administration is also preferred by most parents,
who would rather make one trip to your office than two.
Finally, simultaneous administration
of all needed vaccines helps assure
that children are protected, so it is the right thing to do.
There is one exception to this rule.
In children with functional or anatomic asplenia,
pneumococcal conjugate vaccine- PCV13-
and Menactra brand meningococcal conjugate vaccine should not be
administered at the same visit.
These vaccines should be separated by at least 4 weeks.
This is because children with functional
or anatomic asplenia are at very high risk
of pneumococcal invasive disease and Menactra is thought
to interfere with the antibody response to PCV.
So what about vaccines that are not given simultaneously?
For instance, a child got their one year vaccines
from the primary care provider,
but that practice did not have an inventory control plan
and has run out of varicella vaccine.
Now the child must be rescheduled
for the varicella vaccine.
When should he come back?
The only time that a specific interval should separate two
vaccines not given on the same day is when both
of them are live and both are either injected, or administered
by nasal spray, in the case
of live attenuated influenza vaccine.
If two live injected
or intranasal vaccines are not given on the same day,
they should be separated by at least 4 weeks.
All other combinations including live oral vaccines may be
administered at any time before
or after each other without waiting.
The recommendation to separate live virus vaccines
by at least 4 weeks results from concern
that the vaccine given FIRST could interfere with response
to the vaccine given SECOND.
These concerns were initially based on two 1965 studies
that indicated that recent measles vaccination reduced the
response to smallpox vaccine.
In 2001, the CDC conducted a study using the Vaccine Safety
Datalink system to investigate risk factors
for breakthrough varicella, that is,
children who got chickenpox even though they had been vaccinated.
This study found that children
who received varicella vaccine less than 30 days
after MMR vaccination had a significantly increased risk
of breakthrough varicella.
This risk is lower in those
who received varicella vaccine before, simultaneous with,
or more than 30 days after MMR.
This study provided additional evidence
that interference can occur
between two live vaccines given less than 4 weeks apart.
ACIP recommends that when two injected
or intranasal live vaccines are not given on the same day
but are separated by less than 4 weeks,
the live vaccine given SECOND should be repeated,
unless serologic testing indicates that a response
to the vaccine has occurred.
For example, if a dose of MMR were given 2 weeks after a dose
of varicella vaccine, the MMR should be repeated.
The repeat dose should be spaced at least 4 weeks
after the invalid dose.
I would like to emphasize that live vaccines not given
on the same day need to be separated
by at least 4 weeks only if they are injected or intranasal.
The 4 week separation rule does not apply to rotavirus
or oral typhoid vaccine, which can be administered
at any time before or after any other vaccine.
Remember - generally you can give all routine vaccines
at the same visit.
That is the gold standard.
The alternatives we have discussed here are only
for situations when there has been a problem
and simultaneous administration did NOT occur.
Yabo?
You should always try to keep the child
on the routine schedule.
And make sure the parents know the importance
of keeping on schedule.
But sometimes things just do not go according to plan.
Children sometimes are brought in early.
Or, more commonly, a child is behind in the schedule
and needs to be caught up.
Also, spacing becomes an issue when assessing a record
of vaccines given outside the United States,
since non U.S. schedules may differ from those used here.
Here is the General Rule that applies to this situation.
Increasing, or lengthening, the interval between doses
of a multidose vaccine does not diminish the ultimate
effectiveness of the vaccine,
after the series has been completed.
While an increased interval
between doses does not ultimately reduce antibody
titers or protection, it may compromise protection
in the short run, because the series is incomplete.
However, decreasing the interval between doses
of a multidose vaccine may interfere
with antibody response and protection.
Doses of vaccine given too close together may not provide the
full benefit of the vaccine.
So, if the minimum intervals are so important,
it would seem reasonable
that there should be a table listing them somewhere.
And there is.
This is Table 1 of the General Recommendations on Immunization.
This table contains a listing of every dose
of every commonly used vaccine.
It is also available on the updates and resources web page,
and in the course text.
Here is a closer view of Table 1.
The table has five columns.
The first column on the left lists the vaccines by dose.
The second column indicates the RECOMMENDED AGE for that dose.
This is the age listed for that dose on the childhood schedule.
The third column lists the MINIMUM AGE for that dose.
Vaccine doses should not be given
at an age younger than the minimum age.
The fourth column indicates the RECOMMENDED INTERVAL
to the next dose.
Like the recommended age, this is information derived
from the routine childhood schedule.
The fifth column indicates the MINIMUM INTERVAL
to the next dose.
Doses of vaccine should not be spaced closer
than the minimum interval.
Table 1 provides all the information you need
for scheduling vaccine doses.
Be sure to have a close look at it.
And be sure to read all the footnotes.
The ACIP recommends that providers schedule vaccines
as close to the recommended age and intervals as possible.
The recommended schedule, age for specific doses,
and spacing of doses is supported by data
from clinical trials of the vaccine.
There are times when it is necessary
to give vaccines earlier or closer together than recommended
in the routine schedule.
Minimum ages and intervals can be used in these circumstances,
for instance when a person is behind on the schedule,
and it is necessary to catch them up.
Minimum ages and intervals could also be used in other situations
when the vaccination series may need to be accelerated,
such as when international travel is impending.
While there are less scientific data supporting the use
of minimum intervals and ages, ACIP believes that the response
to doses given at minimum intervals
and ages will be acceptable.
Andrew?
In practice, vaccine doses are sometimes administered
earlier than the minimum age or minimum interval.
In the past, ACIP has recommended that a dose
of vaccine separated from the previous dose by less
than the recommended minimum interval- even one day less-
should not be considered a valid dose.
ACIP continues to recommend
that vaccine doses should not be given at less
than the minimum interval or earlier than the minimum age.
But in an effort to increase the flexibility
of the complicated childhood immunization schedule,
the ACIP now recommends that vaccine doses administered
up to 4 days before the minimum interval
or age can be counted as valid.
This four day period before the minimum age
or interval is sometimes referred to as the grace period.
The ACIP believes
that administering a dose a few days earlier
than the minimum interval or age is unlikely
to have a significant negative effect
on the immune response to that dose.
This four day grace period can be applied to all ages
and intervals listed in Table 1.
However, the grace period does NOT apply to minimum intervals
between different live vaccines.
For example, if MMR and varicella vaccine are not given
on the same day, do not use the 4-day grace period
to shorten the 28-day minimum interval
between these two vaccines.
The grace period should not be used
when scheduling future vaccination visits.
It should be used primarily when reviewing vaccination records,
such as for child care or school entry.
The 4 day grace period may also be useful in situations
where a child visits a provider a few days earlier
than a scheduled vaccination appointment.
For example, if a child comes to the office or clinic
for an ear check 27 days after his or her second DTaP dose,
the provider could administer the third DTaP
at that visit rather than having the child return
for vaccination the next day.
The 4 day grace period recommendation
by ACIP may cause a conflict
with some state school entry requirements.
For instance, most state school requirements mandate the first
dose of MMR to be given on or after the first birthday.
As a result, not all states will accept the grace period
for some or all vaccine doses.
Providers should determine the position
of their state immunization program
on this issue before using the grace period.
The reason that some states do not accept the grace period is
because to do so would mean changing the school requirement
or law, which often requires an act of the state legislature.
So be sure to check with your state immunization program
before using the grace period.
Remember to stay on the routine schedule whenever possible.
But sometimes children fall behind.
If this happens you need to do several things- talk
to the parent about the importance of staying
on schedule; flag the chart for special attention; and speed up,
or accelerate, the vaccination schedule.
This means giving doses with the minimum acceptable intervals
until the child is caught up.
The ACIP and the Academies of Pediatrics
and Family Physicians publish a harmonized catch
up schedule every year with the recommended schedule.
The one you see here is for children 4 months
through 6 years of age.
There is also a version for children 7
through 18 years of age.
The information in the catch
up schedule is basically the minimum interval information
from Table 1 in a condensed and reconfigured form.
You need to be familiar with the catch up schedules.
Be sure to take some time to look at them carefully.
And, of course, read all the footnotes.
The catch up schedules are also available on the CDC vaccines
and immunizations website.
Table 1 of the General Recommendations, and the catch
up schedules address the minimum acceptable interval
between doses.
But what if the interval is too long?
It is not necessary to restart the series of any vaccine due
to an extended interval between doses.
The one possible exception to this is oral typhoid vaccine,
which you are not likely to use unless you deal with travelers.
Extended intervals between doses happen all the time.
Healthcare personnel sometimes decide to take one or two
OR TEN years off between doses of hepatitis B vaccine.
Adolescents may only make it
into their doctor's office once a year.
Sometimes parents just forget,
or do not understand the importance
of staying on schedule.
If the interval between doses is longer
than the recommended interval, you do NOT have
to restart the series or add doses.
Just pick up where you left off, and try to get the rest
of the doses in on time.
Donna?
We would like to take a moment
to briefly discuss combination vaccines.
A combination vaccine is defined
as a product containing components
that can be divided equally
into independently available routine vaccines.
This means that protection
against the same diseases could also be provided
by available separate component vaccines.
Providers have the option
of choosing what alternative works best for them.
Here is the list of combination vaccines that are available
in the United States as of March 2011.
Comvax is Haemophilus influenzae type b, or Hib,
combined with hepatitis B vaccine.
Twinrix is hepatitis A vaccine combined
with hepatitis B vaccine.
Pediarix is DTaP and hepatitis B combined
with inactivated poliovirus, or IPV.
Pentacel is a combination of DTaP and IPV which is used
to reconstitute lyophilized Hib vaccine.
ProQuad is a combination of measles, mumps, rubella,
and varicella vaccines, or MMRV.
Finally, Kinrix is a combination of DTaP and IPV,
which is approved only for the last dose
of the DTAP and IPV series.
Note that MMR is not on this list,
because separate component products for measles,
mumps and rubella are NOT currently available.
Td is not on the list because there is no single antigen
diphtheria toxoid available.
IPV is not on this list because monovalent
and bivalent polio vaccines are not available
in the U.S. There are many arguments for
and against the use of combination vaccines.
Arguments for the use
of combination vaccines include improving vaccine coverage
rates; timely vaccination coverage for children behind
in a vaccination series; and reduced shipping
and stocking costs for the provider office.
Arguments against the use
of combination vaccines include the increased risk
of adverse events that occur with some combinations.
For example there is an increased risk of fever
and febrile seizures with the use of MMRV,
and an increased risk of fever with Pediarix.
Another argument against the use
of combination vaccines includes social factors, like the use
of several different providers by the same patient.
This could lead to sequential use of combination vaccines
that contain different components,
which could complicate the vaccination schedule.
The decision to use a combination vaccine as opposed
to single component products can be a difficult one.
A provider should assess various factors:
the number of injections; the availability of vaccines;
the likelihood of improved coverage; the likelihood
of patient return; storage and cost considerations;
patient preference, and assessment of the risk
of adverse events associated with the use
of a particular product.
The assessment of these factors should help the provider make a
choice about which product to use.
So, the main issues on spacing and timing
of vaccines are the timing of antibody containing products
and MMR and varicella vaccines; spacing of doses
of different vaccines;
and spacing of doses of the same vaccine.
These issues arise frequently in practice,
so you need to be clear on them.
These issues and more are discussed
in the General Recommendations.
We strongly suggest that you get a copy
if you do not already have one, and take some time to read it.
We would like to present a case study that addresses issues
that we have discussed on the program today.
The case studies are available on the updates
and resources web page for this series.
Anna is a 15 month old who has been
in your practice since birth.
She is brought to your office
for routine vaccinations in early June.
At 11 months of age - 4 months ago- Anna was diagnosed
as having immune thrombocytopenic purpura,
or ITP.
She was treated with intravenous immune globulin, or IGIV.
The ITP symptoms have now resolved.
She has no other medical problems.
Here is Anna's vaccination history.
She received Pediarix, the DTaP - IPV -
hepatitis B combination vaccine, at 8, 12, and 20 weeks of age.
At the same visits she also received doses of Hib,
pneumococcal conjugate, and rotavirus vaccines.
Here are three questions about Anna: what vaccines, if any,
should Anna receive today?
When should she return for her next vaccinations?
What vaccines will be needed when she returns?
If you are viewing this program
with a group we suggest you pause the program now
and discuss it among yourselves.
We will return in a moment to discuss it with you.
There are several issues with Anna.
This is actually a fairly complicated situation,
but not one that is rare in clinical practice.
The issue you need to work
through first is whether the vaccines she has received
so far are valid.
For that you would mainly want to consider the ages
and intervals between the doses; There is also the issue
of the ITP and the treatment she received for it.
This could be an issue for vaccines she needs today.
The General Recommendations will be useful
in working through these issues.
Here is the first question about Anna: What vaccines, if any,
should Anna receive today?
Today, Anna needs her third hepatitis B vaccine,
her fourth DTaP, Hib number 4, PCV number 4, and her first dose
of hepatitis A vaccine.
She is also age-eligible for MMR and varicella vaccines,
but she won't get them today.
Why does she need hepatitis B vaccine?
You checked Table 1 in the General Recommendations
and found that the minimum age for the third dose
of hepatitis B vaccine is 24 weeks.
She received her third dose at 20 weeks of age,
which was 4 weeks early.
So the hepatitis B component of the Pediarix dose is not valid
and should be repeated because it was given early.
The minimum intervals between these doses of DTaP,
IPV and pneumococcal conjugate vaccines are 4 weeks.
So these vaccine doses can be counted.
Hepatitis A vaccine is recommended for all children
in their second year of life - between 12 and 23 months.
So you have the opportunity,
and you should give her the first dose today.
The vaccines a person needs may not be the vaccines the person
can receive.
Anna is age-eligible for MMR and varicella vaccines.
But the ITP, and more importantly the IGIV she
received to treat it 4 months ago, make Anna ineligible
for MMR and varicella vaccines at this visit.
Here is the next question about Anna.
When should she return for her next set of vaccinations?
Anna should return for her next vaccinations in 4 months.
That would make it 8 months
after the intravenous immune globulin.
To determine the spacing between the IGIV and MMR
and varicella vaccines you will need another important table
from the General Recommendations -Table 5.
This table lists the recommended interval
between various antibody products and MMR
and varicella vaccines.
Anna received IGIV 4 months ago.
According to Table 5 the interval between IGIV and MMR is
from 8 to 10 months depending on the dose.
We do not know exactly what dose Anna got,
so the soonest she could come back would be 4 months,
which would be the minimum 8 months
after the ITP dose of IGIV.
But it may actually need to be longer.
You need to find out what dose she got
so you can more accurately determine when she should return
for her MMR and varicella vaccines.
She is seeing you in June.
She is going to come back in 4 months, in October.
Here is the last question about Anna:
What vaccines will be needed when she returns?
Assuming that enough time has passed
since her IGIV she will receive her first MMR
and her first varicella.
Since it is October she will also need a dose
of influenza vaccine.
You may consider either separate MMR and varicella vaccines
at this visit, or MMRV.
ACIP recommends that if MMRV is being considered,
one should screen for a history of seizures in Anna
and for a history of seizures in her siblings and parents.
In addition it is important to discuss the risks and benefits
of the MMRV vaccine with her parents.
Unless her parents express a preference for MMRV,
CDC recommends that MMR
and varicella vaccines be given separately rather
than MMRV in this age group.
If she returns in 4 months she will be 19 months old.
She will not yet be old enough
to receive the live attenuated influenza vaccine.
The minimum age for LAIV is two years.
So she will need a dose of inactivated influenza vaccine.
Whether she needs a second dose of influenza vaccine depends
on her past influenza vaccination history.
The minimum interval between doses
of hepatitis A vaccine is 6 months, so she will not
yet be eligible for the second dose at the next visit.
There is one other issue about Anna, and that is the use
of a measles- containing vaccine in a person who has a history
of thrombocytopenia or low platelet count.
A history of thrombocytopenia is a precaution to the use
of a measles- containing vaccine.
It is possible that a person with this history could be
at increased risk of having another episode
of thrombocytopenia should they be exposed to measles vaccine.
The decision to administer MMR to a person with a history
of thrombocytopenia requires your assessment
of risk and benefit.
If you do not vaccinate her the risk
of thrombocytopenia following measles DISEASE would be much
higher than the risk from the vaccine.
The clinician would need
to consider these things very carefully.
In our opinion, in almost every case,
the benefit of measles immunity outweighs the risk
of a recurrence of her thrombocytopenia,
and we would suggest that she receive MMR on schedule.
>> We'd now like to share some frequently asked questions
that we receive, and Yabo, I'll ask the first question to you.
How soon after someone receives vaccines can they donate blood?
>> Okay, very interesting question.
We have information from the American Red Cross
that gives basically varying intervals,
depending on what vaccine was initially given.
For example, there may be a four-week interval
after live viral vaccines whereas with Hepatitis B,
only a seven-day interval.
At CDC, to try to form a consensus,
we've basically recommended
that a four-week interval should be used
after receiving a vaccine before donating blood products.
>> Good, so essentially a four-week interval
after vaccine before donating blood.
>> Yes.
>> Thank you.
Donna, question for you.
Why do we recommend second doses of live vaccines
like MMR varicella vaccine, if they're supposedly so effective?
>> Well, they are very effective,
but there's no vaccine that's 100% effective,
and some people just don't respond to the first dose.
And since measles, mumps, rubella and varicella are
so contagious, we really want to get as high coverage rates
and hurt immunity as we can.
So to try to capture those people that did not respond
to the first dose but who may respond to a second dose,
that's why we recommend that second dose,
because you have somewhere between 5 to 10% of people
who won't respond to that first dose of MMR, and maybe as high
as up to 20% who may not respond to that first dose of varicella.
So it's not really a booster dose;
it's really to capture those people with that second dose
that didn't respond and get those coverage rates
up as high as we can.
>> Great, makes sense.
Thank you.
Yabo, a kind of a case-based type of question.
Let's say if someone is beginning the human
papillomaviruses or HPV vaccine series beginning at 25 years
of age, and then they don't complete the series
but they come back and return at 27 years of age.
Do they finish the series, or do you have to start
over because they're older than 26 years now?
>> Good. There are actually two parts I think to this question.
The first is the issue of maximum interval between doses
of a vaccine in the same series.
Even though it's been a year since the first dose
in the series, you can resume where you left off.
There's no need to restart the series.
So that's one general rule I want to bring home.
Secondly, with the HPV vaccine, the upper limit as far
as the license age for the vaccine is through 26.
So now this young lady is presenting at age 27.
In this case you may complete the series,
even though she started at 25, now she's 27;
she's above the license age; go ahead
and complete the series of the HPV vaccine.
>> Make sure you get all those doses in.
>> Exactly.
>> Very good.
Donna, question about the grace period.
Can the grace period be used for really all types of doses,
even when there is a dose recommended
after the fourth birthday?
>> Well, the answer to that is yes,
in terms of minimum intervals and minimum ages.
Any of those on Table I in the General Recommendations, yes,
you can use the four-day grace period
if it is acceptable to your state.
So you always have to check the state laws and make sure.
But I would caution you to be conservative in your use
of the four-day grace period.
If you need to accelerate things and you can at least stay
within the minimum intervals, that's a better option,
because there's always the possibility
that a child could move to a state
where they don't accept the four-day grace period
and then it would have to be repeated.
So conservative uses is what we recommend.
>> Thank you.
>> That's a good point, Donna, that you brought
up about people moving from state to state
and that could change?
>> Well, and it really also --
the intention really of the four-day grace period is
in terms of evaluation of those doses
that have already been given, and you're trying
to assess whether they are valid doses or not.
So that's really more often
when you see the four-day grace period used.
>> Excellent points.
Yabo, question -- kind of another case-based question
that we receive a lot, has to do with vaccine availability.
If you have let's say, a 12-month-old, that's recommended
for both MMR and varicella vaccine,
and your clinic only has MMR; it does not have varicella vaccine,
what should you do in this situation
with this recommendation?
>> Well, the main thing is you never want
to miss an opportunity to vaccinate,
so in this case you would give the vaccine
that you have available in the office.
Because these are two live viral vaccines,
we do have to separate them, if they're not given
on the same day, by four weeks to avoid interference
from the first vaccine given on the second.
So in this case you would have the child come back
in at least four weeks for the varicella vaccine,
give the MMR today and have them come back in four weeks
for the varicella vaccine.
>> You know, there actually is another option.
If you had to, for some reason, it was urgent to go ahead
and get that varicella dose in,
then what you could do is send them to another clinic.
If they could get there that day, that clinic day,
and get their dose that you couldn't get at your office,
you could do it that way and it would still be acceptable,
but once you get beyond that clinic day,
then if you miss it then, they're going
to have to wait four weeks.
>> Okay. Well, that's all the time we have
for questions for this session.
Thank you very much, Donna, and thank you, Yabo.
[ Background sounds ]
>> This brings us to the close of this session of Epidemiology
and Prevention of Vaccine-Preventable Diseases.
We would like to remind you of resources that you can use
to get more information or to contact us.
Here's the companion book for this program.
The book is a useful resource for any office
that administers vaccines to persons of any age.
The Public Health Foundation is the sole source
for a printed copy.
In addition to the print version,
the 12th edition is also available in an eReader format.
You can contact the Public Health Foundation
through their toll-free number at 877-252-1200.
You can also order materials online
from their website at bookstore.phf.org.
If your patients or their parents have
immunization-related questions, you can refer them
to the CDC Info Contact Center.
You can reach the Contact Center toll-free at 800-CDC-INFO.
The CDC Info Contact Center is staffed from 8:00 a.m.
until 8:00 p.m. Eastern time Monday through Friday.
If you or your staff have questions,
you should direct them to the National Center for Immunization
and Respiratory Diseases by e-mail.
Our e-mail address is NIPInfo@cdc.gov.
Throughout this program we've mentioned several
immunization resources.
You can find links to these and much more
on the Program Resources web page at www.cdc.gov/vaccines.
Click on the Education and Training section,
then the Immunization Courses link.
Choose this program from the list
to find all the materials we've discussed in this session.
It's a good idea to have the most current immunization
information quickly accessible in your office or clinic.
An easy way to do this is
to have the information available on your computer.
We've compiled all of the current ACIP statements,
Vaccine Information Statements, the course text, and much more
on a DVD called "Immunization Works."
It provides a great way to have all your current immunization
information together in one place.
The DVD is distributed free of charge by the CDC.
The Program Resources web page has a link to order it.
Continuing education credit is available
for viewing this program.
Details about the procedure for obtaining CE credit can be found
in the Continuing Education chapter of the DVD
or on the Program Resources web page.
Thank you for joining us for this session of Epidemiology
and Prevention of Vaccine-Preventable Diseases.
We hope you'll join us for other sessions in this series.
Until then, good-bye.