A Study of Immunogenicity and Seroconversion With Sabin IPV Schedules in China.

In April 2017, WHO recommended that a two-dose, Inactivated Poliovirus Vaccine, IPV-only schedule at 4 months and 8 months of age can be used after polio eradication, with a schedule seroconversion target of at least 90%. However, there is no such data for China domestic Sabin strain IPVs to support a 2-dose schedule among Chinese infants. This research is to determine the seroconversion rates among two arms: Group 1: two-dose schedule, infants will be received two doses of Sabin IPV, the first dose at 4 month of age, and the second dose at 8-11 month of age. Group 2: three-dose schedule, infants will be received three doses of Sabin IPV at 2, 3 and 4 month of age respectively. This schedule is currently recommended by manufacture\'s package insert for routine use. The hypothesis is the seroconversion will be above 90% in both groups.