Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, if he will assess the approved covid-19 vaccines' level of protection for those who are vaccinated and registered as clinically vulnerable by monitoring antibody levels.

Public Health England (PHE) will be using existing surveillance systems and enhanced follow-up of cases to monitor how effective the vaccine is at protecting against a range of outcomes including infection, symptomatic disease, hospitalisations, mortality and onwards transmission.

There are a number of studies and surveillance systems that monitor rates of infection in the population through repeat respiratory swabs and blood tests to monitor the development of antibodies against the virus - antibodies due to infection can be distinguished from antibodies due to vaccination. PHE will monitor rates of infection in vaccinated individuals compared to unvaccinated individuals to understand how effective the vaccine is at preventing infection.

To monitor the effectiveness of the vaccine at preventing onwards transmission PHE will look at laboratory markers of infectiousness in vaccinated compared to unvaccinated cases and follow-up household contacts of cases to understand whether vaccination reduces onwards transmission within the household. The impact of the vaccination programme on COVID-19 activity at a population level will be monitored to understand the direct and indirect effectiveness of the vaccine.

Vaccine effectiveness will be monitored in different population groups to understand how the effectiveness varies by age, presence of other medical conditions and other factors. Surveillance systems will remain in place for the long-term to monitor how long protection lasts to inform the need for booster doses.