Antibody Response of Pregnant Women to Poliomyelitis Vaccine and Passive Transfer to Infants

Summary Poliomyelitis vaccine was administered to 80 pregnant women twice during the last trimester. A second group of 62 unvaccinated pregnant women was studied as controls. Blood was obtained from the first group before vaccination and from all mothers at delivery. Cord blood was collected and the infants were bled successively at 24 hr, 1 week, 1, 2 and 3 months of age. All specimens from each mother and infant were tested on the same day for neutralizing antibodies against the three types of poliomyelitis in HeLa cell cultures. As expected, the response of women with prior antibodies was greater than in those with no antibody before vaccination. Statistical analysis of the serum titers of mothers at delivery, cord blood and of the infant at 24 hr showed that there is no significant difference between the poliomyelitis antibody content of the three specimens. The titer of passively transferred antibodies in the infants declined with age at the same rate regardless of whether they had been stimulated naturally with infection or artificially with vaccine. Many infants had demonstrable antibodies at the third month of life but the duration of antibody was a direct function of the height of the antibody titer in the mother at the time of delivery thus demonstrating the value of vaccination in heightening antibody levels of pregnant women and their offspring and indicating the probable protective influence in a period of increased risk.