If you are concerned about an adverse event it should be reported on a Yellow Card. Reporting forms and information can be found at
https://coronavirus-yellowcard.mhra.gov.uk or search for MHRA Yellow Card in the Google Play or Apple App Store. When reporting please include the vaccine brand and batch/Lot number if available.
Please do not report the same adverse event(s) to both systems as all reports will be shared between Pfizer and MHRA (in an anonymized form) and dual reporting will create unnecessary duplicates.