Antipoliomyelitis neutralizing antibodies in maternal and neonatal serum.

During 1993 blood samples were taken from 1251 women consecutively admitted to the Maternity Ward of the University of Parma. Samples were also taken from all the newborn babies. Absence of antipolio neutralizing antibodies in serum diluted 1/2 was shown in 6 mothers; 4 mothers for polio 1, 1 mother for polio 2 and 1 simultaneously for the poliovirus 1 and 3. If one considers only the cases of absence in undiluted serum, there were 2 negative subjects (0.16%). One of these was for antibodies against polio 1 and the other for antibodies against polio 2. In the cord blood samples the frequency of negative results in serum diluted 1/2 is higher: 42 in all with 13 babies negative for polio 1. 17 babies for polio 2, 8 for polio 3 and 2 babies simultaneously for polio 1 and polio 3. If one considers just the babies without antibodies even in undiluted serum, the fraction of seronegatives is 9 (0.7%) with 1 for polio 1, 6 for polio 2 and 1 for types 1 and 3. The Geometric Mean Titres of the antibodies are significantly higher in mothers born before 1964 (year of introduction of mass vaccination with OPV) compared with those born after that year. Likewise, the same phenomenon was observed in the respective children.