Combined Haemophilus influenzae type b and Neisseria meningitidis serogroup C (HibMenC) or serogroup C and Y-tetanus toxoid conjugate (and HibMenCY) vaccines are well-tolerated and immunogenic when administered according to the 2, 3, 4 months schedule with a fourth dose at 12-18 months of age

Combined HibMenCY and HibMenC conjugate vaccines may facilitate inclusion of vaccination against MenC and MenY into routine vaccination schedules, without additional injections. Immunogenicity and reactogenicity of vaccination with three different formulations of a novel HibMenCY-conjugate vaccine, or a HibMenC-conjugate vaccine was assessed. Infants were randomized to receive either Hib(2.5 mu g)-MenC(5 mu g)-MenY(5 mu g)-TT, Hib(5 mu g)-MenC(10 mu g)MenY(10 mu g)-TT, Hib(5 mu g)-MenC(5 mu g)-MenY(5 mu g)-TT or Hib(5 mu g)-MenC(5 mu g)-TT vaccines co-administered with DTPa-HBV-IPV at 2-3-4 months of age. Controls received licensed conjugate MenC-CRM197 vaccine co-administered with DTPa-HBV-IPV/Hib. A fourth dose was administered to a subset of children at age 12-18 months. Anti-PRP concentrations and meningococcal bactericidal (rSBA-MenC/Y) titers were measured prior to and one month post third and fourth vaccination dose. Solicited local, general symptoms and unsolicited adverse events were recorded for 7 and 30 days after each vaccination, respectively. Post-dose-3, all subjects had anti-PRP antibody levels >= 0.15 mu g/ml and rSBA-MenC >= 1:8. 97.0%-98.6% of HibMenCY recipients had rSBA-MenY >= 1:8. Pre-dose-4, 95.6%-100% of HibMenCY and HibMenC recipients had anti-PRP >= 0.15 mu g/ml and 90.7%-97.6% recipients had rSBA-MenC titers >= 1:8. In HibMenCY groups, 78.6%-86.7% had persisting rSBA-MenY >= 1:8. The post-dose-4 response was robust after all vaccines with all subjects having anti-PRP >= 1 mu g/ml and 92.3%-100% rSBA-MenC >= 1:128. All HibMenCY recipients had rSBA-MenY >= 1:128. Vaccination with the novel Hib-meningococcal vaccines had a safety profile similar to control. HibMenCY and HibMenC conjugate vaccine formulations given at 2-3-4 months of age with a fourth dose in the second year of life were immunogenic and had a comparable safety profile to licensed vaccines. (study 792014 and 100381; www. clinicaltrial. govID:NCT00129116).