Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what recent assessment he has made of the durability of the covid-19 (a) vaccine and (b) booster vaccine in holding immunity.

Several studies of vaccine effectiveness have been conducted in the United Kingdom which indicated that, against the Delta variant, two doses had an initial 90% effectiveness against symptomatic infection, waning over six months to 65% to 80% depending on the vaccine. Booster doses were found to restore vaccine effectiveness to over 90%. Protection against severe disease remained high in the first six months after at least two doses. For the Omicron variant, effectiveness against symptomatic infection was lower at an initial 70% after a booster, waning to 10 to 20% after five months. For the Omicron variant, effectiveness against hospitalisation following a booster dose is initially over 90%, waning to 70% after six months.

The UK Health Security Agency continues to assess data on vaccine effectiveness, including immunity to COVID-19. The most recent COVID-19 vaccine surveillance report was published on 1 September. This contains updates on effectiveness of the spring booster programme and against Omicron BA.5 and BA.5 sub-lineages, vaccination in pregnancy and vaccine impact on proportion of the population with antibodies to COVID-19. The report is available at the following link:

https://www.gov.uk/government/publications/covid-19-vaccine-weekly-surveillance-reports