Gap in the prevalence of neutralising antibodies to polioviruses in antenatal women in southern India.

With the disappearance of circulating wild poliovirus and improved sanitation, protective antibody levels may wane over time following oral poliovirus vaccine (OPV) administration. This study evaluated the seroprevalence of neutralising antibodies to vaccine polioviruses among young Indian women who had received at least three doses of OPV as primary immunisation. Of 60 women studied, 27 (45%) had antibody titres of <1:8 to one or more polioviruses, with the lowest levels for poliovirus types 3 and 1. These findings represent a possible immunity gap and this needs to be confirmed with further studies, which could include a challenge with vaccine virus.