| Abstract: | The kinetics of antibody persistence following the administration of a combination meningococcal serogroup C and Haemophilus influenzae type b (Hib) conjugate vaccine (Menitorix) in the second year of life in children primed with two doses of one of three monovalent meningococcal serogroup C (MCC) vaccines was investigated. The study subjects were administered either Menitorix at 12 to 15 months of age, followed by the seven-valent pneumococcal conjugate vaccine (PCV7) and the measles, mumps, and rubella vaccine 4 to 6 weeks later, or all three vaccines concomitantly at 12 to 15 months of age. Blood samples were collected before and 1, 2, 12, and 24 months after the boosting. Sera were analyzed for meningococcal serogroup C serum bactericidal antibody (SBA) and IgG as well as Hib-polyribosylribitol phosphate (PRP)-specific IgG. The antibody persistence data from this study were compared to those of a prior study of Southern et al. (Clin. Vaccine Immunol. 14:1328-1333, 2007) in which children were given three primary doses of a vaccine containing both the MCC and the Hib vaccines but were boosted only with a Hib conjugate vaccine. The magnitude of the meningococcal SBA geometric mean titer was higher for those subjects primed with the MCC vaccine conjugated to tetanus toxoid (NeisVac-C) than for those primed with one of two MCC vaccines conjugated to CRM197 (Menjugate or Meningitec) up to 1 year following boosting. Two years after boosting, the percentages of subjects with putatively protective SBA titers of ≥8 for children primed with NeisVac-C, Menjugate, and Meningitec were 43%, 22%, and 23%, respectively. Additional booster doses of the MCC vaccine may be required in the future to maintain good antibody levels; however, there is no immediate need for a booster during adolescence, as mathematical modeling has shown that persisting herd immunity is likely to control disease for a number of years.A booster dose of meningococcal serogroup C conjugate (MCC) and Haemophilus influenzae type b (Hib) conjugate vaccine was introduced in September 2006 in England and Wales for children in the second year of life in the form of a combined vaccine, Menitorix (GlaxoSmithKline [GSK]), which has tetanus toxoid (TT) as the carrier protein. In England and Wales, infants receive a combined diphtheria toxoid (D), TT, acellular pertussis (aP5), inactivated poliovirus (IPV), and Hib-TT conjugate vaccine (DTaP5/IPV/Hib-TT; Pediacel; Sanofi Pasteur) at 2, 3, and 4 months of age; MCC vaccination at 3 and either 4 or 5 months of age; and a seven-valent pneumococcal conjugate vaccine (PCV7; Prevenar; Wyeth Vaccines) at 2 and 4 months of age. Three different MCC vaccine manufacturers'' vaccines are available: two are conjugated to CRM197, a nontoxigenic natural variant of diphtheria toxin (Meningitec [Wyeth Vaccines] and Menjugate [Novartis Vaccines]), and one is conjugated to TT (NeisVac-C; Baxter Bioscience). Although the data obtained following the administration of the current primary vaccine series in the United Kingdom have been reported (16), antibody persistence following boosting with Menitorix and priming with two doses of each of the licensed MCC vaccines has not been reported. This report details the immunogenicity data for those receiving the MCC and Hib vaccines, by primary MCC vaccine, for before and at 1, 2, 12, and 24 months after a booster dose of Menitorix administered at 12 to 15 months of age. The rates of antibody decline for those receiving the Hib and MCC vaccines are also compared. |
