These reports contain a complete listing of all suspected adverse reactions that have been reported to the MHRA via the Yellow Card scheme for COVID-19 vaccines. This includes all reports received from healthcare professionals, members of the public, and pharmaceutical companies.
This information does not represent an overview of the potential side effects associated with the vaccines. A list of the recognised adverse effects of the COVID-19 vaccines is provided in the information for healthcare professionals and the recipient information here. Conclusions on the safety and risks of the vaccines cannot be made on the data shown in the report alone. When viewing the report, you should remember that:
Reporters are asked to submit Yellow Card reports even if they only have a suspicion that the vaccine may have caused the adverse reaction. The existence of an adverse reaction report does not necessarily mean that the vaccine has caused the reaction.
It may be difficult to tell the difference between something that has occurred naturally and an adverse reaction. Sometimes reactions can be part of the condition being treated rather than being caused by the vaccine.
Many factors have to be considered when assessing whether a vaccine has caused a reported adverse reaction. When monitoring the safety of medicines and vaccines, MHRA staff carry out careful analysis of these factors.
It is not possible to compare the safety of different vaccines by comparing the numbers presented in the vaccine reports. Reporting rates can be influenced by many factors including the seriousness of the adverse reactions, their ease of recognition and the extent of use of a particular vaccine. Reporting can also be stimulated by promotion and publicity about a product.
For a vaccine to be considered safe, the expected benefits will be greater than the risk of having harmful reactions. It is important to note that most people receive vaccinations without having any serious side effects.
For a medicine to be considered safe, the expected benefits of the medicine will be greater than the risk of suffering harmful reactions. It is important to note that most people take medicines without suffering any serious side effects.
All medicines can cause reactions. The patient information leaflet accompanying the medicine, or available from your pharmacist, lists the known side effects associated with the medicine. Healthcare professionals such as doctors and pharmacists can also provide this information. Information on side effects of medicines can be found on the NHS website.
Information collected through the Yellow Card scheme is an important tool in helping the MHRA and CHM monitor the safety of medicines. Yellow Card reports of suspected adverse reactions are evaluated, together with additional sources of evidence such as worldwide literature, in order to identify previously unidentified hazards or side effects.
If a new side effect is identified, information is carefully considered in context of the overall side effect profile for the medicine or vaccine, and how it compares with other medicines used to treat the same condition.
The MHRA will take action, if necessary, to ensure that the product is used in a way that minimises risk, while maximising patient benefit. Such changes may include, for example, restricting the indication, or special warnings and precautions. Rarely, a drug may need to be withdrawn from the market if the risk of side effects is considered to outweigh the benefits of treatment. Please see our How we monitor the safety of medicines section for further information.
If you wish to copy or circulate the information contained within a report to anyone else, please ensure that a copy of these guidelines is also provided.
The MHRA and CHM encourage the use of data from the Yellow Card scheme in research and for publication, but wish to ensure that the limitations of interpretation of the data are made clear.
If you propose to publish information based on Yellow Card data, the MHRA is most willing to provide advice on how the Yellow Card information might be best used and presented. The MHRA is also willing to provide feedback on manuscripts prior to publication. Please write to the Deputy Director, Safety and Surveillance Group by email.