Reporting suspected COVID-19 vaccine side effects, and potential product defects or counterfeit products

Christine Randall, Assistant Director, Lead pharmacist for Dental Medicines Information and Pharmacovigilance, North West Medicines Information CentrePublished Last updated See all updates

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.

PHE 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.

PHE Immunisation Against Infectious Disease (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, after the second dose or after both 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.
  • 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, AstraZeneca  and Moderna 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.

The vaccine manufacturers (Pfizer-BioNTechAstraZeneca and Moderna) advise that if side effects such as pain and/or fever are troublesome, medicines containing paracetamol can be taken.

PHE patient/recipient information advises that even if patients experience symptoms after the first dose, they still need to have the second dose.

PHE have issued a patient/recipient information on COVID-19 vaccination and blood clotting Information about your vaccine

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 associated with COVID-19 vaccines has been issued by:

Also see SPS COVID-19 vaccination and blood clotting

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 weekly (published every Thursday) report covering adverse reactions to available COVID-19 vaccines.

The Coronavirus vaccine – weekly summary of Yellow Card reporting summarises information received via the Yellow Card scheme. It will also include other safety investigations carried out by the MHRA under the COVID-19 Vaccine Surveillance Strategy.

In addition, the weekly summary contains links to Vaccine Analysis Profiles for each vaccine in current use. Vaccine Analysis Profiles list all suspected adverse reactions that have been reported via the Yellow Card scheme for COVID-19 vaccines:

Vaccine Analysis Profile – Pfizer/BioNTech

Vaccine Analysis Profile – Oxford University/AstraZeneca

Vaccine Analysis Profile – Moderna

Vaccine Analysis Profile – brand unspecified

The MHRA is working with PHE to identify potential safety signals as described in the PHE COVID-19 vaccine surveillance strategy.

All MHRA vaccine safety advice and press releases can be found at Vaccines and vaccine safety

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, choose the ‘Defective’ link on the Yellow Card homepage. Once the report has been logged via the Yellow Card Scheme your incident will be assigned a unique MDR# number. This is your individual reference, please retain for your records. Your report is shared with the company using the MDR# number.
  • 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.
  • Report the issue to your Regional Vaccination Operations Centre (NRVOC), 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).

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.

PHE Immunisation Against Infectious Disease (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 as usual on the Yellow Card site.

Change history

  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