Abstract

A field trial on DPT vaccine was carried out in Kecamatan Mojoagung and Sumobito, Kabupaten Jombang, East Java. Samples of 1100 infants aged between 3-8 months were selected randomly from this area. The samples were decided into three groups; group I of 234 infants received DPT-DPT-DT vaccine, group II of 242 infants received DT-DT-DPT vaccine and group III received DPT-DT-DPT vaccine. Injection was 0.5 ml and given deep subcutaneous. The potency and cold chain of the vaccine was tested and fulfilled the requirement: A passive hemagglutination test was used to determine the antitoxin. The immune status against diphtheria in each group was observed before and after immunization. The results were 8.5 - 62.15 % of group I, 10.3 - 64.05 % of group II and 14.2 - 60.93 % of group III respectively. The mean titer of diphtheria antitoxin after immunization in each group was between 0.02 - 0.03 HAU per ml.