Large-scale Use of Sabin Type 2 Attenuated Poliovirus Vaccine in Singapore During a Type 1 Poliomyelitis Epidemic

In the latter half of 1958 Singapore experienced an epidemic outbreak of poliomyelitis due to the type I virus. Eleven weeks after the first case was reported the Minister of Health in the Singapore Government decided, after consultation, to make available the attenuated type 2 vaccine elaborated by Sabin (1957a, 1957b) for children between the ages of 3 months and 10 years. Dr. Sabin agreed to the release of this vaccine on condition that adequate laboratory control could be assured. The following communication gives the reasons for the selection of the type 2 vaccine, the experimental details, and the results of the campaign. TABLE I.-Incidence of Poliomyelitis in Singapore Since 1946 up to Period of Epidemic