Reproductive and Mortality Outcomes in Wistar Rats Following Oral Polio Vaccine Administration

Rumors surrounding the potential side effect of infertility caused by the oral polio vaccine (OPV) have led parents and caregivers in Northern Nigeria to reject the OPVs. Unfortunately, little attention has been given to confirming or refuting this concern, and limited research addresses this gap. OPVs were administered to Wistar rats in varying doses, and their reproductive health and mortality indices were evaluated over a six-week period. The Wistar rats were divided into three experimental groups consisting of 10 male and 27 female rats. Each male rat was paired with three female rats and assigned to one control group and two experimental groups. Pregnancy tests, live delivery outcomes, estrogen and progesterone levels in females, and sperm parameters in males were methodically documented. Pregnancies were recorded in 6 (66%), 6 (66%), and 7 (77%) of the female rats in groups 1, 2, and 3, respectively, resulting in the delivery of 14, 15, and 16 offspring in the three groups. The mean number of pregnancies and deliveries was similar across the three groups, with no statistically significant difference (p>0.05). All male rats showed normal semen parameters. The comparison of mean semen analysis findings among the three groups was not statistically significant, except for sperm motility, which was higher in groups 2 and 3. OPV did not have any detrimental effect on the reproductive performance of both female and male rats. This study demonstrated that OPVs have no effect on the reproductive outcomes in both male and female rats exposed to OPVs.