Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what assessment she has made of the potential merits of including people with weakened immune systems in (a) clinical trials and (b) post-marketing surveillance programmes for vaccines.

Studying vaccines in immunodeficient people can only be done when the characteristics of the immune response have been established for the specific vaccine in healthy individuals. Therefore, this cannot be requested in clinical trials taking place before marketing authorisation is granted by the Medicines and Healthcare products Regulatory Agency (MHRA).

Given the diversity of immunodeficient populations, which is difficult to represent in pre-authorisation clinical trials, the MHRA can recommended at the time of authorisation of a new vaccine that the manufacturer commits to undertaking post authorisation studies focusing on effectiveness and safety in these patient groups. This was the case for the new COVID-19 vaccines authorised in the United Kingdom, given that immunodeficient patients are at increased risk of severe COVID-19.

Another way to collect post-marketing data on the safety of vaccines in immunodeficient groups is by targeted active monitoring. As part of the MHRA’s proactive surveillance strategy to monitor the safety of the COVID-19 vaccines, this was undertaken in certain groups of vaccine recipients, including those with immunodeficiencies. The aim was to compare the frequency and severity of side effects to groups included in the pre-authorisation clinical trials, and ultimately help to further characterise the safety profile of the vaccines in these patient groups.