CDC Reinstates Hib Booster Dose for 12- to 15-month-olds

After more than a year and a half of deferrals, the booster dose of Haemophilus influenzae type b, or Hib, vaccine should again be considered a routine part of the childhood immunization schedule (1-page PDF; About PDFs).

The CDC -- in consultation with its Advisory Committee on Immunization Practices, or ACIP, the AAFP and the American Academy of Pediatrics -- is recommending that physicians immediately reinstate the Hib booster dose for children ages 12-15 months who have completed the three-dose primary series.

"Through appropriate vaccination, family physicians rarely encounter children with serious and life-threatening infections caused by Haemophilus influenzae," said Jonathan Temte, M.D., Ph.D., an associate professor in the department of family medicine at the University of Wisconsin School of Medicine and Public Health, Madison, and a member of the ACIP. "Full immunization for protection against Haemophilus influenzae type b is dependent on the appropriate initial series and the booster dose. As supplies of vaccine have increased, clinicians need to resume this booster dose routinely at age 12 to 15 months."

Temte said a booster dose should be given to older children in whom the booster was deferred (i.e., those as old as age 59 months) at the next routinely scheduled office visit.

CDC said in a Morbidity and Mortality Weekly Report, or MMWR, released June 26 that although supply has increased sufficiently to resume on-time administration of the booster dose in infants ages 12-15 months and begin catch-up vaccination, "supply is not yet ample enough to support a mass notification process to contact all children with deferred Hib booster doses."

Instead, the agency recommended that physicians

The nationwide Hib vaccine shortage started when Merck & Co. Inc. recalled and later suspended production of its Hib-containing vaccine products in late 2007. In response, the CDC, the AAFP and the American Academy of Pediatrics recommended temporarily deferring the Hib booster dose in healthy children not at high risk for invasive Hib disease.

In the interim, manufacturer sanofi pasteur sought to fill the Hib vaccine gap with its monovalent vaccine, ActHIB, and its combined diphtheria, tetanus toxoids, acellular pertussis, inactivated poliovirus and Hib, or DTaP-IPV/Hib, vaccine, which is marketed as Pentacel.

Previously, the CDC had recommended that if DTaP-IPV/Hib was the only Hib-containing vaccine product available, clinicians should use the combination product to complete the primary Hib series, even if it resulted in a child receiving additional doses of other antigens.

In its June 26 MMWR, the agency acknowledged the difficulty of juggling different vaccine formulations (i.e., combination and monovalent vaccines), both during the Hib shortage and now. Still, CDC officials encouraged physicians to ensure that children are brought up-to-date on all routine immunizations, including both Hib and hepatitis B vaccines, "while minimizing extra doses of unneeded vaccines."

"For example, if a provider is using DTaP-IPV/Hib (Pentacel) vaccine to protect infants against Hib disease, the provider should ensure that adequate stock of monovalent HepB vaccine is available to complete the HepB vaccine series," the MMWR article advised. "Children who need the Hib booster and who already have received 4 doses of DTaP should receive monovalent Hib vaccine (ActHIB) as their Hib booster dose. However, if DTaP-IPV/Hib is the only Hib-containing vaccine available, this combination product can be used to complete the series of Hib vaccination, even if the child already has received all the necessary doses of DTaP and IPV."

"The biggest confusion will occur due to the scarcity of single-antigen Hib vaccine, thus requiring clinicians to use combination vaccines to accomplish the Hib booster dose," Temte said. "The use of such combinations may result in extra doses of some components. Given the threat of Hib disease, however, additional doses of other antigens is warranted."

CDC said physicians with questions about their vaccine supplies of monovalent Hib or DTaP-IPV/Hib should contact Sanofi Pasteur at (800) 822-2463. The manufacturer will increase allotments of Hib-containing vaccines based on established purchasing patterns or a practice's birth cohort and estimates of additional vaccine doses needed, the agency said.

Physicians using public vaccine supplies, such as those supplied through the CDC's Vaccines for Children or Section 317 programs, should contact their state or local immunization program to obtain vaccine.