Assessing Efficacy ofHaemophilus influenzaeType b Combination Vaccines

作者：Dan M. Granoff · 发表于：Clinical Infectious Diseases · 年份：2001 · DOI：10.1086/322563 · 被引用次数：34 · 研究领域：Bacterial Infections and Vaccines、Pneumonia and Respiratory Infections、Influenza Virus Research Studies

Regulatory approval of diphtheria and tetanus toxoids and acellular pertussis (DTaP)-based combination vaccines containing Haemophilus influenzae type b (Hib) has been delayed in the US because of difficulty in assessing the effect of lower Hib immunogenicity on vaccine efficacy compared with the immunogenicity of the specific Hib component administered separately. Hib conjugate vaccines confer protection by eliciting serum anticapsular antibody and priming for immunologic memory. Therefore, compelling proof of efficacy would be demonstration that a combination vaccine primes for memory and elicits antibody responses that are not inferior to those elicited by other US-licensed Hib conjugate vaccines, not necessarily the specific Hib component used in the combination. Vaccinated infants also can be considered protected if their serum anticapsular antibody concentrations are > or =0.15 microg/mL immediately before the booster dose given in the second year of life, when antibody concentrations are lowest. These alternative serologic approaches offer a strong scientific and regulatory rationale for licensure of effective DTaP-based Hib combination vaccines.