Studies on Diphtheria-Pertussis-Tetanus Combined Immunization in Children

[摘要] A group of 68 children was given a booster dose of 0.5 or 0.2 ml of DPT vaccine 11–15 mo after the primary vaccination. The serum antibody content of the three systems titrated 30–45 days after booster injection showed that all the children were adequately protected according to generally accepted criteria.Over the range of prevaccination titers studied, a rectilinear relationship was shown to exist in all the three systems between the log prevaccination titer and the log fold-increase in titer after booster injection. The slopes of the 0.2-ml dose were steeper than those of the 0.5-ml dose, moving beyond the hypothetical positions toward the higher initial titer side. The departure was ascribed to the interference effect of high levels of pre-existing antibodies upon the homologous antigens introduced.Some general problems in secondary immunization like the dose-response relationship, the comparison between groups, and the choice of use of large versus small dose, etc., were discussed in the light of the observations made.

[学科分类] 生物科学（综合）