The vaccines affected by the recall, PedvaxHIB and Comvax, contain Hib capsular polysaccharide (i.e., polyribosylribitol phosphate [PRP])
covalently linked to a meningococcal outer membrane protein (OMP)
carrier. The two unaffected vaccines, ActHIB and TriHIBit, are PRP-tetanus toxoid (PRP-TT) conjugate Hib vaccines. PedvaxHIB and Comvax are recommended as a 2-dose primary series (at ages 2 and 4 months), whereas ActHIB is recommended as a 3-dose primary series (at ages 2, 4, and 6 months).
ActHIB and PedvaxHIB also are licensed for the 12-15 month booster dose. TriHIBit is licensed only for the 12-15 month booster dose.
Children who are not at increased risk for Hib disease, as described in this report, and who received PRP-OMP vaccines for only the first or second dose of their routine primary series may be administered PRP-TT to complete the primary series. In these children, a total of 3 doses will complete the primary series. Children who are behind schedule should complete the primary series according to age-appropriate recommendations.1