Pfizer vaccine

Also called the Pfizer/BioNTech vaccine or Comirnaty vaccine

The Pfizer vaccine protects against COVID-19. 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 12 years and over can book their free COVID-19 vaccination now.  It doesn’t matter what your visa or citizenship status is. 

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

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 which 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.

Who should not be vaccinated with the Pfizer vaccine?

At this stage, the Pfizer vaccine should not be used in children under 12 years of age. If you are currently isolating or experiencing symptoms of COVID-19, you should not be vaccinated until you have recovered and met the criteria to stop isolating.

Before vaccination, check with your healthcare provider

Before vaccination, check with your healthcare provider if you:

  • have in the past had a severe allergic reaction or breathing problems after any other vaccine or after being given the Pfizer vaccine
  • have fainted following any injection
  • currently have a severe illness or infection with high fever 
  • have a bleeding disorder, bruise easily or are on a blood thinning medicine
  • are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop
  • have recently received any other vaccine.

Other health conditions and treatments


Latex allergy

It is safe to have the Pfizer vaccine if you have an allergy to latex. The Pfizer vaccine is latex-free. The vial stopper is made with synthetic rubber (bromobutyl), not natural rubber latex.

Before a CT scan

It is important to advise your oncologist or radiographer if you have received the COVID-19 vaccine recently. This is because the vaccine can cause the lymph nodes in your armpit and neck to swell, which can be detected by CT scans used to diagnose and monitor cancers. Depending on the type of cancer, you may be able to ask to have the injection on the opposite side to your tumour. If possible, have the vaccination at least 2 weeks before a scheduled scan or as soon as you can afterwards. Do not delay any treatment.

Having a mammogram

When you attend a mammogram, tell your doctor or radiographer that you have had a COVID-19 vaccination recently. This is because occasionally the vaccine can cause swelling of the lymph nodes in the armpit near to the injection site. This usually settles after a few days after vaccination but may be detectable on a mammogram for up to a few weeks. In this case, it is advised to monitor such lymph node changes for at least 6 weeks after vaccination. You do not need to delay your vaccination or your mammogram.

If you have a compromised immune system or are receiving treatment for cancer

Many people take medicine that suppresses their immune system, especially for the treatment of cancer, severe asthma, autoimmune diseases, or following organ transplantation. Others have health conditions that can affect the immune system, such as HIV infection or kidney failure.

These conditions put you at increased risk from COVID-19. Although you may not respond as strongly to the vaccine as someone with a fully functioning immune system, it is safe for you to get the COVID-19 vaccine. It will provide some protection against COVID-19, particularly against severe and life-threatening disease.

It is important and safe for those receiving active treatment with immunosuppressive medicines to have the COVID-19 vaccine. If you are severely immunocompromised, talk to your GP or specialist before the vaccine appointment about the best timing for vaccination. Ideally, vaccination should be carried out before any planned immunosuppression. 

It is also important for the people around you, in your household, to have the vaccine when it is offered to them to widen your protection.

If you are HIV positive

People with HIV were included in clinical trials for the Pfizer vaccine. Although the data specific to this group is not yet available there are no safety concerns. 

If you are living with HIV, you are encouraged to get the vaccine. 

Based on what we know about people living with HIV and their response to other vaccines:

  • those with a suppressed viral load are likely to have some protection from the COVID-19 vaccine

  • you may have a weaker response to some vaccines, including the COVID-19 vaccine.

If you are newly diagnosed and starting HIV treatment, get advice from your specialist about the timing of your vaccination. Any medicine being taken for HIV is not expected to change effectiveness of the COVID-19 vaccine. The vaccine will not affect HIV medicines.​

How safe is the Pfizer vaccine?

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 the latest Medsafe’s safety reports on the vaccine here: Overview of vaccine reports.

Can I have the Pfizer vaccine if I am pregnant or breastfeeding?

You are strongly encouraged to be vaccinated against COVID-19 at any stage of pregnancy.

  • In pregnancy, the risk of severe COVID-19 complications is much higher than in people who are not pregnant. 
  • The use in pregnancy aligns with recommendations in other countries and is based on international evidence from a large number of people who have already received mRNA COVID vaccines when pregnant. No additional safety concerns have been shown.
  • There is also increasing evidence that antibodies made by the mother after vaccination are shared with the baby in the cord blood that are likely to also protect her newborn baby against COVID-19.

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 and by being vaccinated, you can provide some protection against COVID-19 for your baby in breastmilk. Read more about the use of the Pfizer vaccine in pregnancy and breastfeeding.

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. At the current time there is no evidence of a risk of blood clots with bleeding with the Pfizer vaccine. 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.

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. You can choose whether to have it 21 days apart or 6 weeks apart.

  • Having your doses 6 weeks apart  has been found to provide a better immune response, and also enables more people to get their first dose sooner. 
  • But, there may be some people who are at higher risk, such as immunosuppressed people or those working in higher risk settings like border workers, who may be advised to have their doses three weeks apart. Learn more: time between doses.

It is very important that you receive your second dose. 

After your vaccination

After getting your COVID jab, 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.

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 and the COVID-19 vaccine. Read more: Privacy

How effective is the Pfizer vaccine?

As with any vaccine, the Pfizer vaccine (Comirnaty) may not fully protect everyone who gets it. However, it is highly effective if people have both doses. That means, if you do catch COVID-19, you’re far less likely to fall seriously ill and less likely to transmit the virus to others.

Studies have shown that about 95% of people who received both doses of the vaccine were protected against getting seriously ill.
Learn more: COVID-19 vaccine effectiveness and protection.

Can the Pfizer vaccine be given with other vaccines?

When having the Pfizer vaccine, it is important to have a gap between other vaccinations. This makes it easier to work out which vaccine may be responsible for any side effects.

Flu vaccine: The Pfizer vaccine can't be given within 2 weeks of a flu vaccine. Read more about the COVID-19 vaccine and flu vaccine during 2021.
MMR vaccine: The Pfizer vaccine can't be given within 4 weeks of the MMR or any other vaccine. 

Note that you need 2 doses of the Pfizer vaccine. These are now given 6 weeks apart. 

If you are due for the Pfizer vaccine and the flu vaccine or the MMR vaccine, the Pfizer vaccine takes priority over other vaccines. It is best that you complete the COVID-19 vaccine course before getting the flu or MMR vaccines. However, it is important that you still get your annual flu vaccine and the MMR vaccine if you are due to have it.

What are the side effects of the Pfizer vaccine?

Like all vaccines, the Pfizer vaccine can cause side effects, although not everyone gets them. Some of the side effects of the Pfizer vaccine may temporarily affect your ability to drive or use machines. Read more: After your immunisation

 Side effects  What should I do?
  • Pain/swelling at injection site
  • Tiredness
  • Headache
  • Muscle pain
  • Chills, fever
  • Joint pain
  • This is quite common after having the vaccination.
  • It usually starts a few hours after getting the injection and settles within a few days.
  • Tell your doctor if troublesome.
  • Feeling unwell
  • Ongoing pain in your arm
  • Difficulty sleeping
  • Itching at injection site
  •  Tell your doctor.
  • Weakness in muscles on one side of your face 
  • Tell your doctor immediately or phone Healthline 0800 611 116.
  • Signs of an allergic reaction such as 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.
  • Chest pain, shortness of breath or an abnormal heartbeat (fast heartbeat or irregular heartbeat)
  • These could be signs of the rare side effect myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the sac surrounding the heart). 
  • This side effect is rare, affecting  less than one person in a million people. 
  • If you develop these symptoms tell your doctor immediately or phone Healthline 0800 611 116.
  • Read more: Myocarditis and pericarditis Medsafe, July 2021

Learn more

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

Karawhiua A campaign for whānau, hapū, iwi and Māori communities to help prevent the spread of COVID-19, Te Puni Kōkiri (Ministry for Māori Development), NZ
COVID-19 vaccination rollout for Northland and Auckland The Immunisation Advisory Centre, NZ
Getting vaccinated for COVID-19
 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
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 09 Feb 2021