Comparative efficacy of three measles vaccines in Indian children.
A Comparative study of three types of measles vaccines was undertaken among 1005 children. Of these 527 were vaccinated with the Serum Institute of India (SII) vaccine, 230 with Schwarz (SC) and 248 were vaccinated with Edmonston-Zegreb (EZ) vaccine (imported from Zegreb). Though the majority of children reacted favourably with all the three vaccines (SII: 98.43%; SC: 93.40%; EZ: 93.0%) with a rise in titre, but the percentage of seroconversion was significantly higher with the SII vaccine (p < 0.01). The Schwarz and Edmonston Zagreb vaccines showed significantly less GM titre as compared with the other age group i.e. 9-12 months (p < 0.05). With Serum Institute of India (SII) vaccine the GM titres were almost similar in the different age groups. The overall GM titre obtained with the SII vaccine was significantly higher than the SC vaccine (p > 0.001) as well as the EZ vaccine (p > 0.001). It is of interest to note that among the infants, 22.5% children had measles antibody in them before vaccination.