ABSTRACT
Objective:To compare the polio antibody level of healthy children in Jiangsu Province before and after the conversion of (inactivated poliovirus vaccine, IPV) immunization program.Methods:200 serum samples of healthy children under 5 years old in Jiangsu Province were collected before and after the vaccine conversion, and the neutralizing antibody against poliomyelitis was measured using the micro cell neutralization test. We compared the differences in the positive rate and geometric mean titer (GMT) of polio antibody before and after vaccine conversion.Results:Before vaccine conversion, positive rates of antibody against poliovirus type Ⅰ and Ⅲ were 98.50% and 92.00%, with GMTs of 1∶100.43 and 1∶23.34, respectively. After the conversion, positive rates of polio antibody type I and Ⅲ were 99.00% and 96.00%, GMT were 1∶213.04 and 1∶121.10.Conclusions:There is a difference in immunization effect before and after the polio vaccine conversion, and the antibody level of the population after vaccine conversion is higher than that before vaccine conversion. It is recommended to gradually increase the IPV dose in order to finally achieve the whole course of IPV inoculation.