Intended for healthcare professionals

Letters Release of raw data on covid-19 vaccines

Covid-19 vaccines: we need immediate release of anonymised data from yellow card scheme

BMJ 2022; 376 doi: (Published 22 February 2022) Cite this as: BMJ 2022;376:o414
  1. Richard A Ennos, retired professor
  1. Edinburgh, UK
  1. rennos{at}

I welcome The BMJ’s call for immediate public access to data on experimental vaccine trials undertaken by their manufacturers.1 But there is an even stronger case for public release of the anonymised individual patient data collected under the UK’s “yellow card” covid-19 vaccine adverse events reporting scheme.2 When these data have been publicly released, as in the United States,3 their analysis has been crucial in identifying important safety signals.4

The yellow card scheme is administered by the Medicines and Healthcare Products Regulatory Agency (MHRA), a government body funded by the UK public. The data are largely gathered by NHS staff. Despite this public financing, however, the MHRA has repeatedly refused to release the anonymised individual patient data for independent analysis (FOI 21/640). It argues that data release would be too onerous, yet paradoxically passes these same data to the vaccine manufacturers as a matter of routine (FOI 21/942). The MHRA’s attitude would not be tolerated in the wider science community where access to raw data is now a prerequisite for publication in peer reviewed journals.

The only quantitative data made publicly available by the MHRA comprises a rudimentary summary of total adverse events classified by vaccine type and medical category. Vital information on relevant patient attributes recorded under the scheme (such as age and sex) are not provided, thereby precluding rigorous scientific analysis of vaccine adverse effects. Consequently, there is no opportunity for independent, scientific challenge of the MHRA’s assertions that covid19 vaccine adverse effects are rare and mild.

The safety profiles of the experimental covid-19 vaccines must be kept under strict and independent surveillance in the UK. This can be achieved only with immediate, public release of the anonymised raw data collected under the yellow card reporting scheme.