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, a study has shown.
Previous studies have demonstrated 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 IBV vaccines has been linked with inconsistencies in immunologic responses, Dr. Michael E. Pichichero of the University of Rochester (N.Y.) and his colleagues 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 to that achieved via separate administration of all component vaccines, the investigators enrolled a total of 575 healthy infants from 22 U.S. sites into 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 investigators reported. Additionally, the three groups achieved similar rates of seroprotection for HepB and Hib, and seropositivity for PCV-7 was high in all groups.
Although there were significantly higher rates of fever observed in the combination group, compared with both other groups, “there were no significant differences in rates of fever at or above 102.2° F [39.0° C], and the fevers were short in duration,” the authors said. Additionally, while the rates of irritability and some local swelling were higher with the combination vaccine, there were no group differences in the rates of symptoms for which parents sought medical advice, they said.
Immunogenicity of the combination vaccine was at least as good as that achieved with separate vaccines. DR. PICHICHERO