Oral polio vaccination of children in the tropics. II. Antibody response in relation to vaccine virus infection.

Poliovirus antibody response rates following the administration of trivalent oral polio vaccine (OPV) have been poor in several developing countries. In an attempt to determine if poor seroresponse is due to poor rates of vaccine virus "take" or due to poor serum antibody response to intestinal virus infection, both vaccine virus take and serum antibody response were determined in a group of children given two doses of OPV. In the large majority of seronegative children there was good correlation between the absence or presence of vaccine virus excretion and negative or positive seroconversion, thus showing that the poor seroconversion rates were mainly due to poor rates of vaccine virus take. However, as in several studies from developed countries showing good seroconversion rates, a few instances of antibody response in the absence of detectable virus excretion and fewer instances of virus excretion without detectable antibody response were also found.