Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, whether the criteria used by the Medicines and Healthcare products Regulatory Agency to assess the safety of vaccines includes a threshold number or proportion of reports of (a) immune thrombocytopenia and (b) other adverse effects.

The Medicines and Healthcare products Regulatory Agency (MHRA) continually monitors safety during use of all medicinal products, including vaccines. For COVID-19 vaccines the MHRA implemented a proactive strategy which included prospective safety data collection and use of a range of United Kingdom and international data sources and methodologies. For all products and events each data source is assessed based on its strengths and limitations using appropriate methodologies and statistical thresholds for those data.

The numbers and types of suspected adverse events vary between medicinal products and cannot be used to compare safety profiles as many factors can influence adverse drug reaction reporting such as the extent of use of a product. The MHRA works closely with public health partners in reviewing the effectiveness and impact of the vaccines to ensure the benefits continue to outweigh any possible side effects.