Questions
and Answers
NIP
Answers Your Questions
Haemophilus influenzae type b
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General
Questions
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When
children less than 24 months of age are infected with Hib, why
does the infection not confer immunity but the vaccine does?
When a young child is infected with Hib disease, the child is
exposed to the polysaccharide molecules and a young child’s
immune system is not mature enough to respond. A child who is
vaccinated is exposed to polysaccharide molecules that have
been conjugated to a protein. Their immune system responds much
better to a conjugated polysaccharide than to a polysaccharide
alone. This is a case where the immune response to the vaccine
is better than the immune response to the “natural infection.”
Pink
Book Chapter: Hib. (2/20/03)
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If
a child over 2 years of age and has had Hib disease, should
they be vaccinated?
We
hope this will not happen since Hib disease has become rare
in the U.S. Most cases are occurring in younger children who
have not been vaccinated.
Children
younger than 2 years of age who develop Hib infection do not
respond well to polysaccharide stimulation that occurs during
infection and do not develop immunity as a result of infection.
Therefore, we recommend that these children should complete
the Hib series after recovery from the infection.
Using
the same rationale, children 2 years of age or older who develop
Hib infection should be capable of developing antibody to the
bacteria. So presumably the child would not need further vaccine.
On the other hand, the vaccine would not hurt the child. If
there is any doubt about the strain of Haemophilus influenzae
and whether the infection was truly caused by type b, then you
should take the conservative approach and vaccinate the child.
(02/26/04)
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Does
Hib vaccine provide life-long immunity?
Hib conjugate vaccine has been used for more than ten years
now. Breakthrough Hib disease has not been reported in older
children. Therefore, immunity persists for more than ten years.
We will continue to monitor for breakthrough disease in older
people. (2/20/03)
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Should
an adult who has had a stem cell transplant receive Hib vaccine
even though the vaccine is licensed for children under 72 months
of age?
Yes. The Hematopoietic Stem Cell Transplant recommendations
that came out a few years ago specifically recommended that
Hib should be given to these adults (Vaccination
of Hematopoietic Stem Cell Transplant Recipients –
see pages 5-6). A single dose of Hib vaccine is also recommended
for adults who have a non-functioning spleen or no spleen (ACIP
recommendations for immunodeficient persons – see
page 8 and Table 2). We don’t recommend the vaccine for
very many adults, but for people without spleens and those who
have had a stem cell transplant, a single pediatric dose of
Hib should be administered. (2/20/03)
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Should
we give Hib vaccine to persons with a cochlear implant if they
are 5 years of age or older?
Available information does not suggest children or adults aged
5 years or older with cochlear implants need Hib vaccination.
There is no specific contraindication to using Hib vaccine in
unvaccinated older children and adults, and health care providers
may consider its use in cochlear implant recipients. However,
there also are no data demonstrating clinical benefit of Hib
vaccination for persons with cochlear implants outside the recommended
age range. If Hib vaccine is used in persons aged 5 years of
older, a single intramuscular injection is all that is needed.
For more information about use of Hib vaccine visit this Jan.
11, 1991 [40(RR01);1-7] MMWR article located at http://www.cdc.gov/mmwr/preview/mmwrhtml/00041736.htm.
(8/21/03)
Top
Schedule
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If
a 7 month old child received two doses of ActHIB and then received
a dose of TriHIBit at 6 months of age. Does the Hib dose given
as TriHIBit need to be repeated, and if so, when?
Repeat the dose. Any dose of Hib given as TriHIBit under 12
months of age is not valid. A valid 3rd dose of single-antigen
Hib can be given 4 weeks after the invalid dose. Pink
Book Chapter: Hib and ACIP
General Recommendations. (2/20/03)
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If
a child received a primary series with TriHIBit and another
dose of TriHIBit at 18 months of age, does the child need another
dose of Hib?
This is difficult to answer because there are really no data.
The Hib doses given for the primary series are invalid since
TriHIBit was used. TriHIBit should not be used for the booster
dose unless the child has received at least one prior dose of
Hib. Since the prior doses were invalid, the booster dose is
technically invalid. Therefore, a valid booster dose of single
antigen Hib should be given. Pink
Book Chapter: Hib. (2/20/03)
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If
PedvaxHIB is given for the 1st and 2nd doses, can the series
be completed by adding one dose of another brand of Hib after
12 months of age?
The primary series for PedvaxHib (PRP-OMP) is 2 doses. Any licensed
conjugate vaccine may be used for the booster dose regardless
of what was received in the primary series. Pink
Book Chapter: Hib. (2/20/03)
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If
a child received two doses of Hib vaccine and the second dose
was given at 13 months of age, does the child need a third dose?
It depends on when the first dose was administered. If both
doses were administered at one year of age or after, then 2
doses are all the child needs. If the first dose was administered
before one year of age and the second dose at 13 months of age,
then the child needs one more dose based on the Hib schedule
in the Pink Book. Pink
Book Chapter: Hib. (2/20/03)
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Is
this a valid schedule: Hepatitis B at birth; Comvax at 2 months;
Hib at 4 months; Comvax at 6 months; and Hib at 12-15 months?
Yes. This allows for completion of the Hepatitis B and Hib series
without violating minimum ages and intervals. (2/20/03)
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Does
a child need a 4th Hib if he received 3 Comvax. Why or why not?
No. A 3-dose Comvax series is a complete Hepatitis B series
AND a Hib series, as long as the minimum ages and minimum intervals
for the individual antigens are observed. Comvax contains PedvaxHIB,
which is a 2-dose primary series followed by a booster dose
after 12 months of age. If any other brand of Hib is used for
the primary series (either of the first two doses), then the
child will need a total of 4 Hib doses. (03/04/04)
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If
Comvax is given at 2 and 4 months and the patient isn’t
available at 12-15 months, what should we do when they return
to the clinic later?
You can administer any brands of single-antigen Hepatitis B
and Hib vaccines or you can use Comvax, as long as the child
is not over 59 months of age. If the child is older than 5 years
of age, Hib vaccine is not indicated and single-antigen Hepatitis
B vaccine should be used for the 3rd dose. (2/20/03)
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In
the discussion of Comvax it was stated that you can "use
when either antigen is indicated." Shouldn’t Comvax
be used when both Hepatitis B and Hib are needed and
single antigen Hepatitis B or Hib used if only one component
is due?
You can use single antigen vaccine when only one of the vaccines
is indicated or you can use a combination vaccine. ACIP states
that licensed combination vaccines may used whenever any component
of the combination is indicated and the vaccine’s other
components are not contraindicated. Childhood
Immunization Schedule (see Main footnote) (2/20/03)
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If
a child received Hepatitis B vaccine at birth and Hib vaccine
at 2 and 4 months of age, can you give Comvax at 6 months without
having to give another Comvax again?
Yes, but the child will still need another dose of Hepatitis
B vaccine no sooner than 8 weeks after the 6-month dose of Comvax,
and a booster dose of Hib at 12-15 months of age. (2/20/03)
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Does
a child need a 4th dose of Hib if Comvax is used?
Comvax contains PedvaxHIB. The primary series of PedvaxHIB consist
of two primary doses at 2 and 4 months followed by a booster
dose at 12-15 months, which is the recommended schedule for
Comvax. If any Hib vaccine other than Comvax or PedvaxHIB is
used for the first or second dose of Hib at 2 or 4 months of
age, then a third dose of any licensed Hib is recommended at
6 months of age to complete the primary series. The child will
then need a booster dose of Hib at 12-15 months of age, which
can be Comvax or any licensed Hib vaccine, http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4805a1.htm.
(8/21/03)
- Is
it appropriate to administer Hib-Hep B (Comvax) at 2 and 6 months
to an infant who had hepatitis B vaccine at birth?
No,
you are depriving the child of the dose of Hib at 4 months of
age. It is important to give the Hib at 4 months of age because
one dose at 2 months does not offer adequate protection and
very young children are the ones at greatest risk for Hib disease.
If the child received a birth dose of hepatitis B vaccine and
you are using Comvax, then give Comvax at 2 and 4 months of
age with a final dose at 12-15 months of age. Don’t delay
the schedule and deny the child the complete benefit of the
Hib component. (02/26/04)
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If
an 18-month-old received a primary series with TriHIBit, should
the child receive one more dose of Hib?
Yes, this child does not have any valid doses of Hib at this
time because TriHIBit was used. You can count DTaP doses given
as TriHIBit before 12 months of age, but not the Hib doses.
Hib vaccine is recommended through 59 months of age and the
lapsed Hib schedule states that any child 15 to 59 months of
age with an incomplete schedule should receive one dose of Hib.
This child should be given this protection. Pink
Book Chapter: Hib. (2/20/03)
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What
should we say to private providers who don’t give the
last dose of Hib vaccine until the 18-month check-up?
The ACIP and the American Academies of Pediatrics and Family
Physicians recommend that the last dose of Hib vaccine should
be administered between 12-15 months of age. Children under
2 years of age are at greatest risk for Hib disease. The earlier
they are completely vaccinated, the better they are protected.
(2/20/03)
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If
a child has completed a primary series of Hib vaccinations (2-3
doses) before 1 year of age, but has not received the booster
dose between 12-15 months, at what age does the child no longer
need to receive the booster dose?
Hib vaccine is no longer routinely recommended once a child
reaches 5 years of age.Pink
Book Chapter: Hib. (2/20/03)
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