Kawit

Researchers are comparing the immune response and safety of the Sabin strain and wild strain inactivated poliovirus vaccines sIPV and wIPV given by two different injection methods in healthy infants. This phase IV trial involves 480 infants aged 56 to 84 days and aims to assess which vaccination schedule and injection route produce better immunity and safety profiles. The study is randomized and open-label, focusing on immunogenicity and tolerability of sequential vaccination regimens. Participants are randomly assigned into four groups receiving different sequences of three doses of poliovirus vaccine at 28-day intervals, with some receiving the vaccines intramuscularly and others subcutaneously. The four vaccination regimens include combinations of wIPV and sIPV doses. Each group has two-thirds of infants receiving injections into the muscle and one-third receiving injections under the skin. During the study, infants will be observed for immediate reactions for 30 minutes after each vaccine dose, and guardians will record adverse events for 28 days post-vaccination. Blood samples will be collected before the first dose and about 28 days after the final dose to measure antibodies against poliovirus types. Mothers will also provide blood samples or pregnancy test results to screen for infections that could affect the infant. Researchers will track immune response and safety outcomes throughout the trial, which ends in October 2026.