The status of measles after five years of mass vaccination in the USSR.

Mass vaccination of children from 10 months to 8 years old with the original live vaccine prepared from the Leningrad-16 strain has led to a sharp decline in measles morbidity and mortality, and changed its epidemic pattern. In 1972, after 5 years of mass vaccination, the morbidity rate was 117.5 per 100 000 persons, whereas before vaccination the average annual morbidity rate was about 827.