Kawit

Researchers are evaluating the immune response and safety of Sabin strain and wild strain inactivated poliovirus vaccines (sIPV and wIPV) given in different sequences and injection methods. This Phase IV clinical trial includes healthy infants aged 56 to 84 days and compares four vaccination regimens using either subcutaneous or intramuscular injections. The goal is to determine which method and sequence provide better immune protection against poliomyelitis. A total of 480 infants will be randomly assigned to one of four groups, each receiving three doses of vaccine spaced 28 days apart, with a 14-day window. The groups differ in the combination and order of wIPV and sIPV doses. In each group, two-thirds of infants receive injections into the muscle, while one-third get subcutaneous injections. Mothers will also provide blood samples to test for infections to help identify any perinatal transmission risks. During the study, infants will be observed for immediate reactions after each vaccination. Parents will keep diary cards to record any adverse events for 28 days following each dose. Blood samples will be collected from infants before the first vaccine and about 28 days after the last dose to measure antibody levels against poliovirus types. Serious adverse events will be monitored throughout. The study aims to assess both vaccine safety and immune response over the vaccination period.