Find out the side effects, the reported adverse events and allergic reactions to the Pfizer vaccine.
Last updated: 22 September 2021
On this page:
- Known side effects
- Allergic reactions
- When you’re likely to experience a side effect
- Reported side effects in New Zealand
Like all medicines, the vaccine may cause side effects in some people. Most side effects are mild and don’t last long — they're more common after the second dose.
They won’t stop you from having the second dose or going about your daily life. Some side effects may temporarily affect your ability to drive or use machinery.
Common side effects
In the clinical trials, common side effects were reported in every 1 in 10 to 1 in 100 people. These include:
- pain or swelling at the injection site
- feeling tired or fatigued
- muscle aches
- joint pain
- redness at the injection site
Uncommon side effects
In the clinical trials, uncommon side effects were reported in every 1 in 100 to 1 in 1,000 people. These include:
- enlarged lymph nodes
- feeling unwell
- pain in limb
- itching at injection site
Rare side effects
Temporary one-sided facial drooping and temporary inflammation of the heart wall (myocarditis) have been reported as rare side effects, affecting every 1 in 1,000 to 1 in 10,000 people.
Serious allergic reactions do happen but are extremely rare. They usually show soon after you’ve had your vaccine, which is why you need to wait at least 15 minutes. If you do have a serious allergic reaction, vaccinators are trained to manage these.
If you’ve had an allergic reaction to any vaccine or injection in the past, talk to your vaccinator.
Most side effects show within a day or two after being vaccinated.
|What you may feel||What can help||When this could start|
Pain at the injection site, a headache and feeling tired and fatigued. These are the most commonly reported side effects.
Place a cold, wet cloth, or ice pack on the injection site for a short time.
Do not rub or massage the injection site.
Within 6 to 24 hours
Muscle aches, feeling generally unwell, chills, fever, joint pain and nausea may also occur.
Rest and drink plenty of fluids
Paracetamol or ibuprofen can be taken, follow the manufacturer’s instructions.
Seek advice from your health professional if your symptoms worsen.
Within 6 to 48 hours
If you’re concerned about how you’re feeling
If you’re unsure about your symptoms or if they get worse, call Healthline:
Phone 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.
Adverse events following immunisation (AEFI) for the COVID-19 vaccine are reported to the Centre for Adverse Reactions Monitoring (CARM). We commonly know these as side effects.
Any side effects reported are suspected by the reporter to be caused by the vaccine. It doesn’t always mean the vaccine did cause the side effect.
Medsafe closely monitors and releases a safety report showing this data each week. This shows the most common side effects that people in New Zealand experience after getting the COVID-19 vaccine.
Latest safety report from Medsafe
Medsafe publishes weekly reports summarising the number and type of adverse events following immunisation (AEFI) reported with COVID-19 vaccines. Please note there is a time lag between receipt of AEFI reports and publication of the weekly report.
Timeframe: 20 February to 4 September 2021
COVID-19 vaccine administered: Pfizer/BioNTech (Comirnaty)
Total doses given: 3,857,146
Number of reports received on adverse events following immunisation (AEFI)
This shows the number of reports, not the number of people who experienced an adverse event. One person may report on more than one symptom.
- Total reports received: 15,596
- Total reports that were serious: 602
- Total reports that were not serious: 14,994
The most reported adverse events
The top 10 reported adverse events were:
- Headache: 4,891 reports
- Dizziness: 4,705 reports
- Pain at the injection site: 3,804 reports
- Lethargy: 3,686 reports
- Nausea: 3,394 reports
- Fever: 2,192 reports
- Chest discomfort: 1,689 reports
- Numbness: 1,281 reports
- Musculoskeletal pain: 1,215 reports
- Fainting: 1,116 reports
Serious adverse cases reported
Medsafe publishes detailed safety information about the Pfizer vaccine and provides weekly information on serious adverse events following immunisation with COVID-19 vaccines.
View the full reports
For the full reports, including definitions:
Safety report 27 – 4 September 2021
Safety report 26 – 28 August 2021
Safety report 25 – 21 August 2021
Safety report 24 – 14 August 2021
Safety report 23 – 7 August 2021
Safety report 22 – 31 July 2021
Safety report 21 – 24 July 2021
Safety report 20 – 17 July 2021
Safety report 19 – 10 July 2021
Safety report 18 – 3 July 2021
Safety report 17 – 26 June 2021
Safety report 16 – 19 June 2021
Safety report 15 – 12 June 2021
Safety report 14 – 5 June 2021
Safety report 13 – 29 May 2021
Safety report 12 – 22 May 2021
Safety report 11 – 15 May 2021
Safety report 10 – 8 May 2021
Safety report 9 – 1 May 2021
Safety report 8 – 24 April 2021
Safety report 7 – 17 April 2021
Safety report 6 – 10 April 2021
Safety report 5 – 3 April 2021
Safety report 4 – 27 March 2021
Safety report 3 – 20 March 2021
Safety report 2 – 13 March 2021
Safety report 1 – 6 March 2021
Medsafe is New Zealand’s medical regulatory body which administers the Medicines Act 1981 and Medicines Regulations 1984.