Evolution of the poliomyelitis vaccination program in Costa Rica.

Outbreaks of poliomyelitis in Costa Rica occurred at variable intervals until 1972. The first campaign with Salk vaccine was in 1956 and the first with Sabin vaccine was in 1959. Since then, campaigns have been irregular, depending on the occurrence of outbreaks. Continuous vaccination programs were inaugurated after the last outbreak in 1972, and the coverage of primary health care in rural areas was extended. These programs resulted in high levels of immunization. Since no cases of poliomyelitis have occurred in the last 10 years, we can say confidently that the disease has been eradicated in Costa Rica.