Innate immunity in young children being studied wrt response to COVID and how live attenuated polio vaccine lowered incidence of Covid-19 infection. Caveats and limitations aplenty leading to follow up questions to be answered in future studies.

Medical Mythbusting Commentary for March 22 and 23, 2022

Study links the usage of oral polio vaccines with lower incidence of COVID-19
Children’s antibody responses to COVID-19 are stronger than adults’, study finds

Use of oral polio vaccine and the incidence of COVID-19 in the world