The public health strategy during the SARS-CoV-2 (COVID-19) pandemic of 2020-2021 led to profound changes in social behaviour, affecting not only familial but also wider social interactions. One infant (as above) had known prior PCR-proven SARS-CoV-2 infection but there were two further cases with no known COVID-19 exposure. CORAL will follow the cohort initially until the children are 2 years old, with stool sampling at 6, 12 and 24 months for microbiome diversity analysis and allergy testing and blood RNA and epigenomic testing at 12 and 24 months. [Extracted from the article]