Advice on reporting suspected side effects to COVID-19 vaccines. Also correct mechanisms for reporting suspected defective products and counterfeit products.

Reporting side effects to COVID-19 vaccines

The Medicines and Healthcare products Regulatory Agency (MHRA) request that all suspected side effects to COVID-19 vaccines are reported via the dedicated coronavirus Yellow Card site. The purpose of the Yellow Card Scheme is to provide early warning that the safety profile of a product requires further investigation.  By reporting side effects, everyone can help provide more information on the safety of the vaccines.

In addition to a Yellow Card report, NHSE advise that clinical incidents are also reported as described in the SOP Management of COVID-19 vaccination clinical incidents and enquiries to ensure escalation to national level via the National Incident Coordination Centre Single Point of Contact (ICC SPOC). The SOP provides a ‘Clinical case escalation framework’ algorithm; the fast track incident response (within one hour) pathway subject line should begin ‘URGENT: ACTION REQUIRED’.


The MHRA advise using one of the following routes:

  • The coronavirus Yellow Card site (preferred route).
  • The Yellow Card app (download from the Apple App Store or Google Play Store) (preferred route).
  • The regular Yellow Card site – there is a link to the coronavirus reporting site.
  • The embedded Yellow Card link in clinical IT systems (EMIS/SystmOne/Vision/MiDatabank).
  • Patients without online access can call 0800 731 6789 for free. Monday to Friday between 9am and 5pm.

For suspected adverse reactions use the NHSE SOP Management of COVID-19 vaccination clinical incidents and enquiries to escalate clinical incidents in addition to the Yellow Card scheme.

UK Health Security Agency advise that any adverse reaction to a vaccine should be documented in the individual’s record and their GP should be informed.


ALL healthcare professionals and members of the public (patients or carers) can make reports.


ALL suspected side effects, even minor effects. The vaccines are new and it is especially important that they are monitored closely and any suspected incidents are quickly reported.

UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) states that it is a matter of clinical judgement whether a suspected side effect should be reported or not. Although a reaction might occur in close temporal association with an immunisation, often it can be very difficult to assess whether there is a causal link. If there is any suspicion that the reaction is vaccine-induced, the suspected side effect should be reported.


At any point following administration of the vaccine. This can be immediately after the vaccine is administered or at any time in the following days or weeks. There is no time limit. Side effects can be reported after the first dose, second dose, third dose, booster dose or after all doses if necessary.

What to include

When reporting side effects to vaccines or medicines patients and healthcare professionals are encouraged to provide as much information as possible, the MHRA states that the following information should be provided:

  • Information on the person who has experienced the side effect (essential).
  • The name of the vaccine suspected to have caused the side effect (essential). Include the vaccine brand and batch/lot number if available.
  • Whether the side effect is related to the first, second, third or booster dose of the vaccine.
  • The date of the vaccination(s).
  • A description of the side effect (essential).
  • Any other medicines being taken around the same time, including non-prescription and herbal remedies (if available, if not please do not let this prevent you submitting a report).
  • Any other health condition that the person who experienced the side effect may have (if available, if not please do not let this prevent you submitting a report).

Information for patients

Section 4 of the recipient information leaflets for the Pfizer-BioNTech (Adult and Child), AstraZeneca , Moderna, Novavax and VidPrevtyn Beta vaccines state that like all medicines, the vaccines can cause side effects, although not everybody gets them. In clinical studies with the vaccine, most side effects were mild to moderate in nature and resolved within a few days with some still present a week after vaccination. Side effects that occurred in clinical trials with COVID-19 vaccines are listed.

Patients are advised that if they get any side effects, to talk to their doctor, pharmacist or nurse. This includes possible side effects not listed in the leaflet.

Patients who think they have suffered a side effect are encouraged to report it/them on a Yellow Card. Reporting information can be found at the coronavirus Yellow Card reporting site. Patients should include the vaccine brand and batch/lot number if available, you can find this information under ‘Your COVID-19 vaccine record’ if you have the NHS app.

UKHSA patient/recipient information advises recipients what to expect after they have had their primary or booster vaccination. Also What to expect after your child’s COVID-19 vaccination for parents.

UKHSA patient/recipient information and the vaccine manufacturers (Pfizer-BioNTech, AstraZeneca, Moderna, Novavax and VidPrevtyn Beta)  advise that if side effects such as pain and/or fever are troublesome, medicines containing paracetamol can be taken.

The MHRA have produced a leaflet for children and young people Reporting a possible side effect to a COVID-19 vaccine – a guide for Children and Young People

UKHSA have issued patient/recipient information on COVID-19 vaccination and blood clotting

Patient information on side effects is also available on the NHS website page, Coronavirus (COVID-19) vaccines side effects and safety

Information on known side effects for healthcare professionals

Information on side effects, reported in clinical trials, is available in section 4.8 of the manufacturers’ ‘Information for healthcare professionals’:

Information on risk of blood clots, myocarditis and pericarditis, and Guillain-Barré Syndrome associated with COVID-19 vaccines has been issued by:

Suspected side effects (adverse reactions) reported via the Yellow Card scheme

Following publication of the Commission on Human Medicines’ COVID-19 Vaccine Surveillance Strategy, which describes the MHRA’s activities for proactive vigilance of COVID-19 vaccines, the MHRA are producing a monthly report covering adverse reactions to available COVID-19 vaccines.

COVID-19 Vaccine reports for each vaccine in current use are available from the Yellow Card website. COVID-19 Vaccine reports list all suspected adverse reactions that have been reported via the Yellow Card scheme for COVID-19 vaccines and are updated monthly.

All MHRA vaccine safety advice and press releases can be found at Vaccines and vaccine safety. and on the Coronavirus Yellow Card reporting site, see Latest News.

Reporting defective vaccines

The MHRA advise that any potential defects identified by healthcare professionals should be managed as follows:

  • Do not use the vial for vaccinations.
  • Do not discard the vial, instead please keep it aside in a secure place as further investigation may be required. Take a photo of any visible defects if possible.
  • Complete a Yellow Card for a defective medicine/vaccine, enter the name of the medicine/vaccine in the search box and click ‘Start report’. In the ‘What does your report relate to?’ field choose ‘A suspected defective product’. Once the report has been logged via the Yellow Card Scheme your incident will be assigned a unique MDR# number. Your report is shared with the company using the MDR# number. For further information contact
  • Once the company has your MDR# a unique company reference number will be generated. Both the MDR# and company reference are unique to your complaint, please retain for your records.
  • If, when completing your Yellow Card report, you consent to being contacted please wait for instructions from the company or MHRA before taking any further action. The company may request samples/high definition images within the initial acknowledgment letter. DO NOT send any samples without prior notification by the MHRA or company.
  • Report the issue to your Regional Vaccination Operations Centre (RVOC), via the agreed escalation process, including batch number and any other relevant details. The RVOC will escalate unusual or significant defects to the National Vaccination Operations Centre (NVOC).

See also the additional MHRA resource – Defective vaccines reporting process

Vaccine Specific advice:

Please DO NOT report the same adverse event(s) to both the company and the MHRA as all reports will be shared in an anonymised form (the MDR#) and dual reporting will create unnecessary duplicates. For further information contact

UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) states that where the defect is noticed after the vaccine has been administered, advice on management of the patient should be sought. NHSE advise that the preferred route is via the Regional Vaccination Operations Centre (RVOC).

Defective vaccines should be recorded in local stock management/reconciliation systems.

Reporting counterfeit vaccines

The MHRA advise that counterfeit or fake vaccines should be reported on the Yellow Card site, enter the name of the vaccine in the search box and click ‘Start report’. In the ‘What does your report relate to?’ field choose ‘A suspected fake product’. For any queries involving counterfeit or fake medical devices contact

Update history

  1. Link to NHSE document 'Management of COVID-19 vaccination clinical incidents and enquiries' updated
  1. Removed information about and link to the monthly 'Coronavirus vaccine – summary of Yellow Card reporting' which his no longer published. All other information and links checked and correct.
  1. Links to information on VidPrevtyn Beta added.
  1. Links updated. Links to Novavax vaccine added.
  1. Additional bullets in 'What to include' to capture which vaccine dose and dates. Links and advice related to reporting defective and counterfeit medicines updated to reflect new Yellow Card website.
  1. Link to UKHSA's What to expect after your child’s COVID-19 vaccination added
  1. Links to SPCs/PILs updated, added link to the MHRAs leaflet on side effects for children and young people, added advice for recipients on where to find the brand and batch number of the vaccines they have received, link to NHS website side effect page added. UKHSA links to information on rare side effects added. MHRA advice on reporting defective vaccines expanded.
  1. All links and information checked.
  2. PHE information for recipients updated to reflect booster dose and advice to use paracetamol to manage side effects.
  1. Reporting defective medicines section amended to remove advice to send defective vials to Pfizer. Contact details for contacting vaccine manufacturers about adverse events and defects amended, details for Moderna added.
  1. Manufacturers information for the Pfizer-BioNTech vaccine now links to Comirnaty SmPC
  1. Link to Moderna vaccine analysis profile added
  1. Links to resources on COVID-19 vaccines and clotting added
  1. Links to Moderna patient and healthcare professional information added
  1. Additional information highlighting need to escalate clinical incidents via the NHSE SOP Management of COVID-19 vaccination clinical incidents and enquiries.
  1. Links to the MHRA's weekly summary of Yellow Card reporting and to Vaccine Analysis Profiles.
  1. Manufacturer link for Pfizer-BioNTech vaccine changed to Comirnaty SmPC
  1. Published