Indirect protection from COVID-19 for children, from vaccinated parents

A new study based in Israel reveals that parental vaccination confers substantial protection for unvaccinated children in the same household. Vaccination exerts its effect through direct protection of vaccinated individuals, and through indirect protection of individuals living in vaccinated communities. In Israel, the BNT162b2 (Pfizer-BioNTech) mRNA Covid-19 vaccine authorization was extended in May 2021 to children and adolescents aged 12 years or older and in November 2021, it was extended to children aged 5 years or older. Using integrated data repositories of Israel’s largest healthcare organization, Samah Hayek et al. investigated the question of whether older and vaccinated household members reduce the risk of infection to younger children who were not vaccinated. They studied two periods separately – an early period (January 17, 2021 - March 28, 2021) and a late period (July 11, 2021 - September 30, 2021). Regardless of household size, they found that parental vaccination substantially reduced the risk of children up to age 12 becoming infected by reducing the probability of contacting an infectious individual and by a reduction in infectiousness of a vaccinated person who suffers a breakthrough infection. “These results reinforce the importance of increasing vaccine uptake among the vaccine-eligible population to curb the spread of the SARS-CoV-2 pandemic and protect those who cannot be vaccinated,” say the authors.