Pfizer COVID-19 vaccine

Also called the Pfizer/BioNTech vaccine or Comirnaty vaccine

The Pfizer vaccine protects against COVID-19. It protects you from severe infection, hospitalisation and death. Find out about the vaccine and possible side effects.

On this page, you can find the following information:

Who can get the Pfizer vaccine?

Everyone in Aotearoa New Zealand aged 5 years and over can book their free COVID-19 vaccination now. It doesn’t matter what your visa or citizenship status is. 

Tamariki aged 5–11 will receive the children’s (paediatric) version of the Pfizer vaccine, with a lower dose and smaller volume. It is also given using a smaller needle. Read more about Pfizer COVID-19 vaccine in children 5 years old and over.

The Pfizer vaccine is a highly effective vaccine for preventing you getting the coronavirus disease COVID-19, which is caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2).

Vaccination means that if you do become infected you are far less likely to become seriously ill or spread the virus to others.

How does the Pfizer vaccine work?

The Pfizer vaccine works by preparing your body to defend itself against COVID-19. The Pfizer vaccine does not contain the virus itself and cannot cause COVID-19.

The Pfizer vaccine is called an mRNA vaccine. It contains a molecule called mRNA that has instructions for making the spike protein on the surface of the virus. The virus needs this spike protein to enter your body’s cells.

When you are given the vaccine, some of your cells will read the mRNA instructions and temporarily produce the spike protein. Your immune system will then recognise this protein as foreign and produce antibodies to attack it. If, later on, you come into contact with the SARS-CoV-2 virus, your immune system will recognise it and be ready to defend your body against it. The mRNA from the vaccine does not stay in your body but is broken down shortly after vaccination. Learn more about the mRNA vaccines.

How safe is the Pfizer vaccine?

The Pfizer vaccine is safe. Before vaccines are provided to the community, they must be approved by Medsafe, the New Zealand Medicines and Medical Devices Safety Authority. Medsafe only grants consent for a vaccine to be used in New Zealand once they are satisfied it’s safe and effective enough to use. It has given provisional approval for the use of the Pfizer vaccine, the same kind of approval given to the annual flu vaccine.

Medsafe is monitoring the safety of the vaccine as it is rolled out around the country. You can read Medsafe’s latest safety reports on the vaccine here: Overview of vaccine reports.

Who should not be vaccinated with the Pfizer vaccine?

The Pfizer vaccine has an excellent safety profile and there are only a handful of people in Aotearoa who cannot receive it.

  • It is currently not licensed for use in children under 5 years of age.
  • If you are currently isolating or experiencing symptoms of COVID-19, you should not be vaccinated until you have recovered and have met the criteria to stop isolating.
Before the first dose
  • If you have had a previous severe allergic reaction (anaphylaxis) to an ingredient of the vaccine. This is very rare, and only applies to previous anaphylaxis to a stabiliser in the vaccine called polyethylene glycol (PEG). However, this is often unclear as problems with PEG most commonly occur after having it by mouth and there may not be any problem with having it in a vaccine. This will be assessed by an immunology specialist.
After problems with the first dose
  • If you have had a severe allergic reaction (anaphylaxis) usually within 15 minutes after the first dose. Increasing experience now shows that many people can be revaccinated safely in a specialist immunology clinic setting. 
  • If you have had myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the lining around the heart) after your first dose. Myocarditis or pericarditis after the vaccine is rare. Diagnosis requires special tests and often assessment by a heart specialist. 

Learn more about who can't have the Pfizer/BioNTech COVID-19 vaccine.

People with other allergies

  • Some people develop delayed allergic type symptoms to the vaccine, such as hives and other skin rashes. These people can safely get their second dose (see delayed allergic symptoms below).
  • People with a history of allergy to foods and venom can be vaccinated.
  • People with a history of severe immediate allergic response (anaphylaxis) to another vaccine or multiple medicines can receive this vaccine but are asked to wait to be observed for a little longer after vaccination.

Can I have the Pfizer vaccine if I am pregnant?

You are strongly encouraged to be vaccinated against COVID-19 at any stage of pregnancy. A Medsafe review of the use of the Pfizer vaccine in pregnancy found no safety concerns (Safety of the Comirnaty (Pfizer COVID-19) vaccine during pregnancy.) Read more about COVID-19 and pregnancy.  

Can I have the Pfizer vaccine if I am breastfeeding?

You can get the Pfizer vaccine if you are breastfeeding. There are no safety concerns about giving the Pfizer vaccine to people who are breastfeeding. By being vaccinated, you can provide some protection against COVID-19 for your baby through your breastmilk. Read more about the use of the Pfizer vaccine in pregnancy and breastfeeding.

Can the COVID vaccine affect fertility?

No, the Pfizer vaccine will not affect your genes or fertility. The mRNA from the vaccine does not enter the nucleus of any cells, which is where your DNA is. Read more about Comirnaty and fertility. 

Should I get a vaccine if I have already had COVID?

Information from clinical trials, and from countries where there have been a lot of COVID-19 cases, have shown that the vaccines are safe and effective for people who have been infected with COVID-19. The full primary course and booster is recommended. You should start, or continue, with your vaccinations 12 weeks (3 months) after you have recovered from COVID-19. 

How is the Pfizer vaccine given?

The Pfizer vaccine is given as an injection into the muscle of your upper arm by a trained healthcare professional. You will be given one dose, followed by a second dose 3 weeks later (these are called your primary doses). 

Booster doses

In view of the Omicron variant, it is recommended that anyone 16 years and older gets their booster dose.

  • People 18 years and older: you can get your booster dose 3 months after completing your primary course.
  • 16 and 17 year olds: you can get your booster dose 6 months after completing your primary course.

Read more about the booster dose.

Third primary dose

For people with compromised (weakened) immune systems, they are advised to get an additional third primary dose of the vaccine. This additional dose of the vaccine is intended to improve an immunocompromised person's response to their primary doses. Read more about COVID-19 vaccine third dose for severely immunocompromised people. 

After your vaccination

A trained healthcare professional will keep an eye on you for at least 15 minutes after being given the Pfizer vaccine to make sure you don't have any reaction to the vaccination. Read more about getting your vaccination and what to expect.

Is my health information protected?

Yes, your information is protected under privacy laws. When you get your COVID-19 vaccination, you will be asked to provide some personal information, such as your name and the date you get your vaccination. It will recorded by the Ministry of Health in a computerised information system called the COVID-19 Immunisation Register. This is similar to how childhood vaccinations are already recorded in the National Immunisation Register (NIR). 

This information may be used to help you manage your health and for the Government to deliver health services such as the COVID-19 vaccination rollout. It will be treated with care to make sure your privacy is protected, as required by the Privacy Act 2020 and the Health Information Privacy Code 2020. Read more about privacy.

Can the Pfizer vaccine be given with other vaccines?

All vaccines (except the shingles vaccine) can be given at the same time or immediately before or after the COVID-19 vaccine. Read more about the COVID vaccine and other vaccines.

What are the common side effects of the Pfizer vaccine?

Like all vaccines, the Pfizer vaccine can cause side effects, although not everyone gets them. They are more commonly reported after a second dose and in younger adults (aged under 55 years). Read more: After your vaccination.

 Side effects  What should I do?
  • Pain at injection site
  • Tiredness
  • Headache
  • These are the most common side effects after having the vaccination.
  • They usually start within 6–24 hours after getting the injection. 
  • Place a cold, wet cloth or ice pack on the injection site for a short time.
  • Do not rub or massage the injection site.
  • Tell your doctor if they bother you.
  • Muscle aches
  • Chills
  • Fever
  • Joint pain
  • Feeling unwell
  • Nausea
  • These side effects usually start within 6–48 hours after getting the injection. 
  • Rest and drink plenty of fluids.
  • They may be more common after your second dose of the vaccine.
  • Paracetamol or ibuprofen can be taken but follow the manufacturer’s instructions.
  • Seek advice from your health professional if your symptoms get worse.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.

Is there a risk of allergic reaction with the Pfizer vaccine?

Serious allergic reactions can occur but they are extremely rare. New Zealand vaccinators are trained to manage these. Most people with a history of anaphylaxis to other medicines, vaccines, foods and venom can be safely vaccinated.

Signs of an allergic reaction include skin rash, itching, swelling of your lips, face and mouth, or difficulty breathing. 

  • A trained healthcare professional will observe you for at least 15 minutes after being given the Pfizer vaccine 
  • If these symptoms develop after that, go straight to the emergency department at your nearest hospital, or call 111 if your hospital is not nearby.

Delayed allergic symptoms

Some people develop delayed allergic symptoms such as swelling around your eyes or face, hives or a rash. This can develop from a few hours to days after getting your vaccine. The symptoms may settle on their own without treatment or you can use antihistamine tablets (eg, cetirizine or loratadine). Tell your doctor if you are concerned.

Most people who develop delayed allergic symptoms with the first dose can safely get the second dose. You can take an antihistamine (eg, cetirizine or loratadine) prior to or following the second dose. Most people will have a similar milder reaction with the second dose.

Is there a risk of myocarditis with the Pfizer vaccine?

There have been very rare reports of myocarditis and pericarditis occurring after vaccination with the Comirnaty Pfizer COVID-19 vaccine. Note that infection by COVID-19 is far more likely to cause myocarditis than vaccination.

What we know so far:

A Medsafe and CARM (Centre for Adverse Reactions Monitoring) review of the reports of myocarditis and pericarditis received up to 1 December has found that:

  • Symptoms usually appear within 1–5 days after receiving the Pfizer vaccine.
  • Younger men are more likely to have symptoms.
  • Overall, the rate of myocarditis (including reports of myopericarditis) was 7 cases per million people vaccinated after the first dose and 10 cases per million people vaccinated after the second dose. This can be compared with the finding from hospital discharge data in Aotearoa New Zealand (collected before COVID-19 vaccinations were being given) that an average of 95 people were diagnosed with myocarditis every year from 2008–2019.
  • Most cases of myocarditis following Pfizer COVID-19 vaccination are mild and resolve within a short time with standard treatment and rest.
  • For advice about receiving further doses of the vaccine, speak to your doctor.
  • Learn more about the review of myocarditis and pericarditis cases.


In the first few days after your vaccination seek medical attention if you experience:
  • new onset chest pain (or an increase in the severity of existing chest pain), discomfort or heaviness
  • shortness of breath or difficulty breathing
  • an abnormal heartbeat, a racing fluttering feeling or a feeling of skipped heart beats
  • dizziness, feeling lightheaded or fainting which may also occur with the symptoms above.
These are potential signs of myocarditis and pericarditis.

If you have children, please watch them for any decreased activity and ask them to tell you about any symptoms. Children may not realise they have symptoms or may not talk about them without being asked.

For the latest reports on adverse events following immunisation with COVID-19 vaccines, see Overview of vaccine reports.

Is there a risk of blood clots with bleeding with the Pfizer vaccine?

Medsafe has completed a review of the risk of rare cases of blood clots with bleeding reported internationally with some COVID-19 vaccines. To date, all the cases that have been reported after vaccination are linked to the first dose of Vaxzevria (AstraZeneca) or the Janssen COVID-19 vaccines. These vaccines are not currently used in New Zealand. Medsafe continues to monitor this safety signal and remains in contact with international regulators. Read more about COVID-19 vaccines and blood clots.

Does the Pfizer vaccine cause unexpected vaginal bleeding or period problems?

No, there is no evidence to suggest a link between vaccination with the Pfizer vaccine and unexpected vaginal bleeding or period problems (menstrual disorders). A full review by Medsafe of all reports of menstrual disorders or unexpected vaginal bleeding following vaccination, as well as the international published literature, and post-marketing safety reports provided by the Sponsor (Pfizer) did not find any link to the vaccine.

Menstrual disorders and unexpected vaginal bleeding occur commonly in the population, regardless of vaccination, and there are many possible underlying causes, including anxiety caused by the ongoing pandemic. Any changes occurring after COVID-19 vaccination are likely to be temporary, and there is no evidence that these temporary changes will affect future fertility. Read more about menstrual disorders and Comirnaty.

Learn more

For other reliable and accurate information about COVID-19 vaccines, see:

Getting vaccinated for COVID-19
 The Immunisation Advisory Centre, NZ
Update around management of those with allergic reaction to their first dose of Comirnaty or history of PEG allergy The Immunisation Advisory Centre, NZ


  1. Comirnaty COVID-19 vaccine Medsafe Consumer Information, NZ
  2. Comirnaty European Medicines Agency
  3. Time between doses of COVID-19 vaccine extended Unite against Covid-19, NZ, 2021
  4. Myocarditis and the mRNA COVID-19 vaccine in New Zealand - information for health professionals The Immunisation Advisory Centre, NZ

Additional resources for healthcare professionals

COVID-19 education The Immunisation Advisory Centre, NZ
How the Comirnaty (Pfizer/BioNTech) vaccine works and how we assess its safety The Immunisation Advisory Centre, NZ, 2021

Credits: Sandra Ponen, Pharmacist. Reviewed By: Maya Patel, MPharm PGDipClinPharm, Auckland Last reviewed: 24 Dec 2021