Question to the Department of Health and Social Care:

To ask Her Majesty's Government how the ability to transmit COVID-19 differs between someone who has been vaccinated and someone who has been infected with COVID-19.

An assessment on the ability to transmit COVID-19 between those who have been vaccinated and those who have been infected with COVID-19 has not been made. Several studies such as SIREN, Vivaldi and the Office for National Statistics Community Infection Survey have provided evidence that vaccines are effective at preventing infection and therefore transmission.

Results from the SIREN study indicate that vaccination was 85% effective in healthcare workers after two doses, compared to an 84% lower risk of subsequent infection in healthcare workers with natural immunity. The COVID-19 Infection Survey concluded that vaccine-acquired protection remains at least as good as natural immunity. In both people with and without prior natural infection, vaccination provides the highest level of protection.