Antibody Response in Infants to the Poliomyelitis Component of a Quadruple Vaccine

ORAL POLIOMYELITIS VACCINATION BJuA vaccinated regions was initiated in November, 1958, and repeated random collections of stool specimens were made throughout 1959 and 1960. In 1958-9 a total of 2,322 specimens was collected in the four vaccinated regions, and 2,964 specimens in 10 non-vaccinated provinces; in 1960 a total of 7,486 stool specimens was collected from healthy children throughout the whole country. At least three important observations can be made from the results gained hitherto. (1) The initial spread of viruses which foUows their mass introduction into the child population is self-limited, and the attenuated strains (Sabin) do not appear to persist in a community longer than a few months. (2) There is no evidence that the attenuated viruses spread beyond the regions into which they had been introduced. (3) An extraordinarily reduced spread of polioviruses could be demonstrated at the peak of the season, after the nationwide use of oral vaccine in the spring of 1960.