Polio antibody outfit of newborns and infants born after 20 years of mass vaccination with live poliovaccine.

Antibodies against type 1 and 2 poliovirus were tested in 250 infants and against type 3 poliovirus in 341 infants aged 0-13 months to compare the polio antibody outfit of newborns and infants born to three groups of mothers: (a) nonvaccinated, above 35 years of age; (b) vaccinated with attenuated poliovirus but having had chance of contact with wild poliovirus during childhood, age 22-35 years, and (c) vaccinated but not having had contact with wild poliovirus, below 22 years of age. Over 90% of newborns had specific neutralizing antibodies against all three poliovirus types. With increasing infant age the percentage of antibody-positive infants decreased: by age 9-11 months only 46%, 27% and 14% of infants displayed antibodies to polio-virus types 1, 2 and 3, respectively. Geometric mean titres decreased accordingly. Differences between infants born to mothers of the above three groups were nonsignificant: the results obtained suggest that future newborns will also possess satisfactory levels of antibodies acquired from mothers who have only had contact with attenuated vaccine poliovirus.