New Combination Vaccine

Excerpted by Edgar K. Marcuse, MD, MPH, FPIDS, FAAP from the Journal of the Pediatric Infectious Disease Society:

A biologics license application for a hexavalent vaccine (Vaxelis) was approved and licensed by the FDA on December 21, 2018. The vaccine contains diphtheria-tetanus-acellular pertussis vaccine (DTaP), inactivated polio vaccine (IPV), Haemophilus influenzae type b (Hib polyribosylribitol phosphate-outer membrane protein [PRP-OMP]), and hepatitis B (HepB). The vaccine is the product of a joint venture with Merck and Sanofi Pasteur (Lyon, France). The manufacturer reports that adequate supplies will not be available until at least 2020. The vaccine is to be administered in a 3-dose series at 2, 4, and 6 months of age. The results of several prelicensure studies that demonstrated safety and immunogenicity were presented.

The Hib component is the same as that in PedvaxHIB (PRP-OMPC), except that it uses 3 μg instead of 7.5 μg. There is some concern with this formulation, because American Indian/Alaska Native children, who are at significantly higher risk for Hib disease, are preferentially recommended to receive PRP-OMP–containing Hib vaccines because they do not respond as well to and in fact suffer breakthrough disease with other vaccine formulations. The immunogenicity conferred by the new hexavalent vaccine after dose 2 is similar to that of 7-μg–containing Hib vaccines. However, there is a burden of Hib disease in Native American infants younger than 4 months, and limited data are available to show that it provides protection equal to that of the 7-μg formulation after only 1 dose. The consideration for the ACIP is if the new hexavalent vaccine should receive a preferential recommendation for the American Indian/Alaska Native population. The work group currently feels that immunogenicity data after the first dose in this population are needed before the ACIP considers a preferential recommendation.

Other than the aforementioned American Indian/Alaska Native issue, the new hexavalent vaccine will not require an ACIP vote, because the individual components are already recommended; however, it will require a Vaccine for Children Program vote.