EPIDEMIOLOGY AND CONTROL OF MEASLES IN TH E UNITED-STATES - 30 YEARS OF VACCINATION

Measles vaccine has been available and widely used in the United State s for 30 years. During the first 20 years, the incidence of measles dr amatically decreased and the Department of Health hoped that the disea se would be eradicated from the United States by 1982. Yet, as early a s 1970, some American epidemiologist started to doubt whether it would be possible to attain this goal with a single dose schedule. From 198 9, many outbreaks have occurred in some inner-cities. This resurgence shows that the existence of small non-immune population groups is suff icient for a persistant and epidemic transmission of the disease. New control measures were proposed, and evaluated, to increase the vaccina tion coverage of these populations and to prolong the immunity of adol escents vaccinated in their early childhood. With 30 years experience, the description of the modifications of the epidemiological character istics of measles following mass vaccination is useful for countries w hich became involved in such programmes more recently.