Coadministering the seven-valent pneumococcal conjugate vaccine and a Haemophilus influenzae type b conjugate vaccine with the pentavalent diphtheria, tetanus, acellular pertussis, hepatitis B, and polio combination vaccine in infants does not compromise the safety and immunogenicity of the latter vaccine, according to Dr. Michael E. Pichichero of the University of Rochester (N.Y.) and his colleagues.
Previous studies have shown comparable safety and immunogenicity of both the pentavalent vaccine containing diphtheria and tetanus toxoids, acellular pertussis, hepatitis B, and inactivated poliovirus vaccines (DTaP-HepB-IPV) and the separate administration of the component vaccines when the H. influenzae type b vaccine (Hib) is administered to both groups. However, the coadministration of the seven-valent pneumococcal conjugate vaccine (PCV-7) with separate DTaP, Hib, HepB, and IPV vaccines has been linked with inconsistencies in immunologic responses, the authors said (J. Pediatr. 2007;151:43–9).
To compare the immunogenic impact of coadministration of the PCV-7 and Hib vaccines with the combined DTaP-HepB-IPV vaccine with that achieved by separate administration of the component vaccines, the researchers enrolled 575 healthy infants from 22 U.S. sites in the current study and randomly assigned them to one of three conditions: Combination Vaccine Group (DTap-HepB-IPV plus PCV-7 and Hib), Separate Vaccine Group, or Staggered Vaccine Group (DTap-HepB-IPV plus Hib, with PCV-7 administered 2 weeks later). The vaccines were administered at each of the three primary immunization visits at 2, 4, and 6 months of age.
With respect to diphtheria, tetanus, pertussis, and poliovirus antibody responses, the immunogenicity of the combination vaccine coadministered with Hib and PCV-7 “was at least as good as” that achieved with the separate and staggered vaccine schemes. The three groups achieved similar rates of seroprotection for HepB and Hib, and seropositivity for PCV-7 was high in all groups. Despite higher rates of fever observed in the combination group, there were no significant differences in rates at or above 102.2° F [39.0° C], and the fevers were not longlasting or clinically important.