Seroconversion in different age groups after measles vaccination

Seroconversion following measles immunisation was studied in 439 children aged below 9 to 25 months. The anlaysis of age specific seroconversion rate revealed that only 78 · 9 per cent children in the age group below 9 months was seroconversion rate was not observed with further increase in the age of immunisation. The finding supports the recommendation that 9–12 months is the earliest age for satisfactory active immunisation against measles in India. The use of potent measles vaccine in the immunisation programme was monitored by potency testing of samples recalled from the field.