Comparative study of the reaction-causing properties and the immunological and epidemiological effectiveness of Leningrad-16 and Schwarz live measles vaccines.

This study is another in the WHO series of comparisons of measles vaccines prepared from different strains of virus. The Leningrad-16 strain was compared with the Schwarz strain in a trial with children aged 1 to 6 years. A group inoculated with placebo was included as a control.Pyrexias and rashes were more common in the Leningrad-16 group than in the Schwarz group but in neither were the reactions serious. Antibody responses were good in both groups.During the 12 months after vaccination, measles occurred in 5% of the children known to have been exposed to infection in the Leningrad-16 group, 6% in the Schwarz group and 58% in the control group.