RESPONSE OF ADULTS IN ICELAND TO LIVE ATTENUATED MEASLES VACCINE.

Measles has had particularly serious effects when epidemics have occurred in isolated susceptible adult populations and hence the newly developed measles vaccines may be of special importance to these groups. This paper reports on one of the first sizeable trials of live-virus vaccine (Enders Edmonston B strain) in a group of measles-susceptible adults. Over 700 persons, mostly adults, were vaccinated in Iceland in 1962. Detailed records of the reactions in the vaccinated and control groups were obtained and serological tests were made on paired serum specimens. The reactions in all age-groups were basically similar and showed only minor differences in severity. The incubation period was found to increase progressively with age. As well as confirming the general safety of the Enders live measles virus vaccine in adults, this study provides new information on the nature of the reactions induced by measles vaccine and on the comparative immunological response of various age-groups.