Vaccine resources for health and social care professionals - Vaccine safety
Contraindications and special considerations
- Contraindications and special considerations on the green book, chapter 6.
- Emergency treatment of anaphylactic reactions: Guidelines for healthcare providers.
Adverse events following immunisation
- Vaccine safety and adverse events following immunisation on the green book, chapter 8.
- Surveillance and monitoring for vaccine safety on the green book, chapter 9.
Vaccines induce protection by eliciting active immune responses to specific antigens. There may be predictable adverse reactions (side effects): most are mild and resolve quickly. However, it is not always possible to predict individuals who might have a mild or serious reaction to a vaccine.
Following guidance on contraindications will ensure the risk of serious adverse effects is minimised. For more information about vaccines offered in Wales and the diseases they help protect against, visit the list of vaccinations for health and social care professionals page.
Reporting vaccine safety issues
The Yellow Card Scheme is vital in helping the Medicines and Healthcare products Regulatory Agency (MHRA) monitor the safety of vaccines in the UK. All serious suspected adverse drug reactions (ADRs) for established medicines and vaccines should be reported, even if the effect is well recognised. Causality does not have to be proved to report a suspected ADR, only a suspicion is needed.
- Making medicines and medical devices safer
- The Yellow Card scheme: guidance for healthcare professionals, patients and the public
- Yellow Card reporting for healthcare professionals – All Wales Therapeutics and Toxicology Centre
For urgent issues related to a suspected defect in a vaccine the MHRA Defective Medicines Reporting Centre, contact MHRA.
The public and healthcare professionals can find further information on the work of the MHRA agency, safety warnings, and how to report any problems at the UK Government website.
Patient Safety Wales supports NHS organisations to improve patient safety.
The World Health Organisation (WHO) keeps a register of reliable validated websites which can be recommended to parents and professionals.
The Vaccine Safety Net is a global network of websites, established by the World Health Organization, that provides reliable information on vaccine safety.
Vaccine alerts
The latest MHRA safety warnings, alerts and recalls can be found at the UK government website.
Black triangle scheme
New vaccines that are under additional monitoring have an inverted black triangle symbol (▼) displayed in their package leaflet and summary of product characteristic, together with a short sentence explaining what the triangle means – it does not mean the vaccine is unsafe. All suspected ADRs for these vaccines should be reported. Find information on the Black Triangle Scheme.
Surveillance and monitoring for vaccine safety
Surveillance and monitoring for vaccine safety on the green book, chapter 9.
Vaccination surveillance information can be found at:
Vaccine damage payment scheme
Vaccine Damage Payment Scheme on the green book, chapter 10.
The Vaccine Damage Payment Scheme provides a single, tax-free payment to people (or their families) who have suffered severe mental and/or physical disablement as a result of immunisation against certain diseases.
Page last reviewed: 9th April 2026