Immunogenicity and reactogenicity of diphtheria, tetanus and pertussis toxoids combined with inactivated polio vaccine, when administered concomitantly with or as a diluent for a Hib conjugate vaccine
N. Knutsson et al., Immunogenicity and reactogenicity of diphtheria, tetanus and pertussis toxoids combined with inactivated polio vaccine, when administered concomitantly with or as a diluent for a Hib conjugate vaccine, VACCINE, 19(31), 2001, pp. 4396-4403
In an open trial. 400 infants were randomized to vaccination with a combine
d diphtheria-tetanus-pertussis-inactivated polio vaccine (DTaP-IPV) either
mixed with a Haemophilits influenzae type b (Hib) tetanus toxoid conjugate
immediately before injection (DTaP-IPV/Hib (mix)) or given concurrently wit
h the Hib conjugate at separate injection sites (DTaP-IPV + Hib (sep)). The
pertussis component consisted or pertussis toxoid alone. The vaccines were
given intramuscularly at 3, 5 and 12 months of age. No vaccine-related ser
ious adverse events occurred. Local reactions were evaluated from diary car
ds completed by the parents. Infants who received DTaP-IPV/Hib (mix) experi
enced fewer local reactions. Sera were obtained 28-45 days after the second
and third vaccinations. Total Hib capsular antibodies were similar in the
two groups after the second injection but lower in the group receiving DTaP
-IPV/Hib (mix) than in the group receiving DTaP-IPV + Hib (sep) after the t
hird injection (geometric mean 6.1 vs 10.4 mug/ml). Mixing of the vaccines
also led to somewhat lower diphtheria toxin antibodies (5.9 vs 7.7 IU/ml af
ter the third injection) while tetanus antibodies were higher (3.9 vs 2.5 I
U/ml after the third injection). Antibodies against pertussis toxin and the
three polio virus types were similar in the two groups. The moderate impai
rment of the Hib antibody response caused by mixing of the Hib conjugate wi
th aluminium adsorbed DTaP may be due to physicochemical interference but i
s probably of little clinical importance because of the ability of the Hib
conjugates to induce an immunologic memory. (C) 2001 Published by Elsevier
Science Ltd.