Side effects of COVID-19 vaccines

Find out about side effects and what to do if you experience them.

Common side effects

Like all medicines, COVID-19 vaccines may cause side effects in some people. This is the body’s normal response and shows the vaccine is working.

Pfizer/BioNTech vaccine (Comirnaty) 

The most common reported reactions are:

  • pain at the injection site
  • a headache
  • feeling tired or fatigued
  • muscle aches
  • feeling generally unwell
  • chills
  • fever
  • joint pain
  • nausea.

These are usually mild and won't stop you from having the second dose or going about your daily life.

Learn more about who can have the Pfizer/BioNTech vaccine and what it contains

If you feel uncomfortable

You can:

  • place a cold, wet cloth or ice pack on the injection site for a short time
  • rest and drink plenty of fluids
  • take paracetamol or ibuprofen.

When to seek help

If you have side effects or feel unwell after your vaccination, speak with your family doctor or call Healthline on 0800 358 5453.

If you’re concerned about your safety, call 111. Tell them you’ve had a COVID-19 vaccination so they can assess you properly.

Allergic reactions

If you’ve had a severe or immediate allergic reaction to any vaccine or injection in the past, tell the person giving you the vaccine.

Serious allergic reactions do happen but are extremely rare.

If you have a reaction when getting the vaccine, a health worker will be there to treat you immediately.

Report side effects

If you experience side effects (also known as adverse events) after receiving a COVID-19 vaccine, we encourage you to report them.

How to report side effects

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