Safety and immunogenicity of a diphtheria, tetanus, and acellular pertussis-inactivated poliovirus vaccine/Haemophilus influenzae type B combination vaccine administered to Taiwanese infants at 2, 4, and 6 months of age.
BACKGROUND
Combined vaccines are urgently needed to ensure compliance with the increasing number of recommended vaccines for children. We evaluated the safety and antibody response to a diphtheria, tetanus, and acellular pertussis-inactivated poliovirus vaccine/Haemophilus influenzae type b (DTaP-IPV/Hib) combination vaccine administrated to infants at 2, 4, and 6 months of age.


METHODS
Sixty healthy infants between 6 and 12 weeks of age were enrolled. One group of vaccines received the DTaP-IPV/Hib in a single injection, while another group concurrently received DTaP-IPV and Hib at separate injection sites. Solicited adverse events were monitored by parental observation and were recorded on a diary card. Levels of serum antibodies to DTaP and polyribosyl-ribitolphosphate-tetanus (PRP-T) antigens were collected before the first vaccine dose and 1 month after the third vaccine dose.


RESULTS
The combined-injection group tended to have lower local reactions, and there was no increase in reactogenicity when compared with the separate-injection group. Seroconversion rates were 100% in both groups for all antigens, except for the anti-polio 2 antibody in the combined-injection group (96.4%). The combined-injection group had lower antibody levels of PRP (8.45 microg/ml) than did the separate-injection group (20.61 microg/ml). However, the percentage of vaccines achieving protective levels of antibody to PRP (> or = 0.15 microg/ml or > or = 1.0 microg/ml) was similar in both groups.


CONCLUSIONS
DTaP-IPV/Hib may be safely and effectively administered to healthy infants, using a 2-, 4-, and 6-month vaccination schedule. This combined vaccine is cost-effective, more acceptable to parents and physicians, and minimizes distress to infants.
Lin
Tzou-Yien
TY
Division of Pediatric Infectious Diseases, Chang Gung Children's Hospital, Taipei. pidlin@cgmh.org.tw
Wang
Ying-Hsiang
YH
Chang
Luan-Yin
LY
Chiu
Cheng-Hsun
CH
Huang
Yhu-Chering
YC
Tang
Haiwen
H
Bock
Hans L
HL
D000907:Antibodies, Bacterial / Q000276:immunology; D016667:Bacterial Capsules; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000276:immunology*; D018073:Haemophilus Vaccines; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D007223:Infant; D011054:Poliovirus Vaccine, Inactivated / Q000276:immunology*; D011135:Polysaccharides, Bacterial; D013624:Taiwan; D014611:Vaccination; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology*
D000907:Antibodies, Bacterial; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D011054:Poliovirus Vaccine, Inactivated; D011135:Polysaccharides, Bacterial; D017778:Vaccines, Combined