Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, for what reason the MHRA uses observed analyses instead of expected analyses in assessing the safety of Covid-19 vaccines.

The Medicine and Healthcare products Regulatory Agency uses both observed and expected analysis in their assessment of safety signals for COVID-19 vaccines. Data obtained from the spontaneous Yellow Card reporting system, through which patients, public and healthcare professionals can report any incident associated with a medical product, was used to calculate ‘Observed’ figures. Estimated ‘Expected’ figures for pre-determined events were based on the total number of patients who had received the vaccine and the background rate of the event within a pre-pandemic period, using large electronic healthcare record databases. It should be recognised that the purpose of observed versus expected analyses is not to confirm the presence, absence, or magnitude of risks but to provide an alternative approach to rapid signal detection, in addition to disproportionality approaches, to maximise the value of spontaneous reports.