The UK Health Security Agency continues to work with the Medicines and Healthcare products Regulatory Agency, NHS England and other government, devolved administration and academic partners to monitor the COVID-19 vaccination programme. Several studies of vaccine effectiveness have been conducted in the United Kingdom against different COVID-19 variants and continue to be updated.
Post implementation effectiveness studies are required to understand vaccine effectiveness against outcomes such as severe disease and onwards transmission, effectiveness in different subgroups of the population, against different variants and the duration of protection. Vaccine effectiveness is estimated by comparing rates of disease in vaccinated individuals to rates in unvaccinated individuals. Where available, we are focusing on data related to the Omicron variant which is currently dominant in the UK.