Yellow Card Scheme
The UK's pharmacovigilance reporting system for adverse drug reactions including vaccines
The Yellow Card scheme is the UK's system for collecting information on suspected adverse reactions to medicines and vaccines. Operated by the Medicines and Healthcare products Regulatory Agency (MHRA), it is one of the world's longest-running pharmacovigilance systems, established in 1964 following the thalidomide tragedy.
Post-Brexit, the Yellow Card scheme operates independently of EudraVigilance, making it a distinct and important data source for UK-specific vaccine safety monitoring.
Key Facts
History
Established in 1964 by Professor Bill Inman following the thalidomide tragedy. One of the world's oldest pharmacovigilance systems. Named after the original yellow reporting cards distributed to doctors.
Who Can Report
Healthcare professionals, patients, carers, and parents can all submit Yellow Card reports. This open reporting model maximises signal capture, particularly for patient experiences not captured through clinical encounters.
Public Data Access
Yellow Card data is publicly searchable via the Yellow Card website. MHRA publishes regular drug safety updates and vaccine analysis prints (VAPs) with aggregated data.
Post-Brexit Independence
Since the UK left the EU in 2021, MHRA operates independently from EMA. Yellow Card data is no longer shared with EudraVigilance, making it a separate and complementary data source for global surveillance.
How Yellow Card Works
- Reports submitted online at yellowcard.mhra.gov.uk, via the Yellow Card app, or through healthcare providers
- MHRA reviews all reports and follows up on serious or unexpected reactions
- Statistical signal detection applied to identify unexpected patterns
- Signals reviewed by the Commission on Human Medicines (CHM) for regulatory action
- Findings published in Drug Safety Updates and Vaccine Analysis Prints
Role in COVID-19 Vaccine Safety
- UK was among the first countries to identify the TTS signal with the AstraZeneca vaccine (March 2021) — contributing to global regulatory action
- MHRA published weekly Vaccine Analysis Prints throughout the rollout providing unprecedented transparency on adverse event reporting
- Identified myocarditis signal for mRNA vaccines — coordinated with EMA, FDA, and WHO
- Yellow Card data directly informed JCVI recommendations on vaccine choice by age group
Limitations
- Voluntary reporting means significant underreporting — estimated 10% of serious reactions and 2–4% of non-serious reactions are reported (Hazell & Shakir, 2006)
- Cannot determine causation — reports indicate suspected associations only
- High-profile media coverage can temporarily inflate reporting rates, complicating signal detection
- Post-Brexit, UK data no longer pooled with EU data, reducing statistical power for rare event detection
Sources & Citations
UK MHRA. "Yellow Card Scheme." Medicines and Healthcare products Regulatory Agency. https://yellowcard.mhra.gov.uk
UK MHRA. "Coronavirus (COVID-19) Vaccine Analysis Print." Gov.uk. https://www.gov.uk/government/publications/coronavirus-covid-19-vaccine-adverse-reactions
Hazell L, Shakir SA. "Under-reporting of adverse drug reactions: a systematic review." Drug Safety. 2006;29(5):385-396. https://doi.org/10.2165/00002018-200629050-00003
MHRA. "About the Yellow Card scheme." Gov.uk. https://www.gov.uk/report-reaction-medicine