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

Source:
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

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