Intro: Children and Young people were the last group in England be offered COVID-19 vaccination (from September 2021). thus were the largest susceptible group when SARS-CoV-2 Omicron variants emerged. We monitored vaccine and naturally-derived antibodies in schools between November 2021 and March 2022. Methods: We conducted three large surveys (November 2021. https://jalyttlers.shop/product-category/pudding-basin/