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Haemophilus influenzae type b (Hib)

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Haemophilus influenzae type b (Hib)

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Haemophilus influenzae type b (Hib)
What's the difference between Haemophilus influenzae type b and influenza?
Haemophilus influenzae type b is a polysaccharide-encapsulated bacteria that causes a variety of invasive diseases, such as meningitis, epiglottitis, and pneumonia. Influenza is a virus that causes the disease influenza.
Historical note: Haemophilus influenzae was first isolated in 1889 from the sputum of a patient who died of influenza, and the isolated organism (then called the Pfeiffer bacillus) was assumed to have caused the patient's illness. Haemophilus influenzae received its name in 1920, to acknowledge its historical association with influenza. The viral cause of influenza was not discovered until 1933.
If a dose of Hib vaccine was given by mistake to a 2-week-old, should further doses of Hib vaccine be given?
Limited data suggest that Hib vaccine given before 6 weeks of age may induce immunologic tolerance to Hib antigen and reduce the response to subsequent doses. As a result, Hib vaccine should not be given earlier than 6 weeks of age. However, if a dose was administered before 6 weeks of age, it should not be counted as part of the Hib series. A full series of 3 or 4 doses, depending on the product used, should be started at 2 months of age as usual. No special protocol or testing is recommended for children who received a dose of Hib vaccine before 6 weeks of age.
What is the Hib schedule for children who have fallen behind or are completely unvaccinated?
Healthcare providers should refer to the catch-up schedule which is approved and published each year by the ACIP, AAP, and AAFP. Depending on the child's previous Hib vaccine history, this schedule will be able to establish the number of further doses needed and the minimum intervals between doses. However, if a child receives a dose of Hib vaccine at 15 months of age or older, he or she does not need any further doses regardless of the number of doses received before 15 months of age.
Can all of the licensed Hib-containing vaccines be used interchangeably?
Yes, with one exception. The GSK Hib monovalent product (Hiberix) is only licensed for the booster dose.
If Hiberix is inadvertently given as some or all of the doses of the primary series, do the doses need to be repeated?
If an infant received one dose of Hib at 5 months, and another at 15 months, does he/she need any more doses?
No. If a child receives a dose of Hib vaccine at 15 months of age or older, he or she does not need any further doses regardless of the number of doses received before 15 months of age.
Since the booster dose of Hib vaccine can be given at 12-15 months, is it still necessary to "boost" two months later if the first dose was given at 12-14 months?
If the child received a primary series (2 or 3 doses) of Hib vaccine in the first year of life, then the final (booster) dose of the series may be given as early as 12 months, provided at least 2 months have passed since the last dose. An unvaccinated 12-14 month old child should receive one dose as a primary series, and a booster dose 2 months later. Unvaccinated children 15-59 months of age need only a single dose of any licensed conjugate Hib vaccine.
A 4-year-old received dose #3 of Hib at age 6 months. Does the child need dose #4?
Yes. All children less than 5 years old need at least one dose of Hib vaccine on or after the first birthday. The last dose should be separated from the previous dose by at least 2 months.
I've just evaluated a 7-year old who does not have a record of receiving Hib vaccine. Would a dose be indicated now?
ACIP does not recommend routine Hib vaccination of healthy children 59 months of age or older, even if they have no prior history of Hib vaccination.
Which adults should receive Hib vaccine?
Hib vaccine is not routinely recommended for healthy adults 19 years and older, even if the person did not receive Hib vaccine as a child. However, ACIP recommends that Hib vaccine can be administered to persons with sickle cell disease, leukemia or HIV infection, or who have anatomic or functional asplenia if they have not previously received Hib vaccine. One standard pediatric dose of any Hib vaccine may be used.
When should Hib vaccine be administered to a person having a splenectomy?
When elective splenectomy is planned, vaccination with pneumococcal, meningococcal, and Hib vaccines should precede surgery by at least 2 weeks, if possible." If vaccines are not administered before surgery, they should be administered as soon as the person's condition stabilizes post-operatively.
Should adult patients who are not asplenic but who have hypogammaglobulinemia receive Haemophilus influenzae type b (Hib) conjugate vaccine? The February 2014 Hib ACIP statement includes immunoglobulin deficiency in its "high-risk groups" for Hib disease, but the recommendations seem to imply that Hib vaccine is not necessarily for adults with immunoglobulin deficiency whose spleens are intact. Am I interpreting ACIP correctly on this matter?
You are interpreting the recommendations correctly, and age is an important factor in this issue. The recommendation for Hib vaccination for asplenia applies to persons of all ages. The recommendation for Hib vaccination for immunoglobulin deficiency applies only to children 12 through 59 months of age.
If a child receives a different brands of Hib vaccine at 2 and 4 months of age should a dose also be given at 6 months of age?
Yes. If different brands of Hib vaccine are given at 2 and 4 months of age then the child should receive a third primary dose of either vaccine at 6 months of age. A 2-dose primary schedule (e.g., doses at age 2 and 4 months) is only appropriate when both doses are Merck's PedvaxHib.
This page was reviewed on February 25, 2015
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