Pfizer COVID-19 vaccine

Also called the Pfizer/BioNTech vaccine or Comirnaty vaccine

The Pfizer vaccine (also known as the Pfizer/BioNTech vaccine or Comirnaty) protects against COVID-19.

On this page, you can find the following information:

What is the Pfizer vaccine?

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). The Pfizer vaccine is available to people 16 years of age and older.

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 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.

As with any vaccine, the Pfizer vaccine may not fully protect everyone and it is not known how long you will be protected for.

Who should not be vaccinated with the Pfizer vaccine?

The Pfizer vaccine vaccine should not be used in children under 16 years of age.

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 weakened immune system, such as due to HIV infection, or are on a medicine that affects your immune system
  • have a bleeding disorder, bruise easily or are on a blood thinning medicine
  • are pregnant or breastfeeding, think you may be pregnant or are planning to have a baby
  • 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.

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. To date, there are no concerns about the adverse effects reported. You can read the latest Medsafe’s safety reports on the vaccine here: Overview of vaccine reports.

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 1 dose followed by a second dose at least 21 days later. It is very important that you receive your second dose.

A trained healthcare professional will keep an eye on you for at least 30 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 long does protection from the Pfizer vaccine last?

Data from Medsafe shows that protection from the Pfizer vaccine lasts for at least 2 months. As part of the conditional approval of the Pfizer vaccine, more data is to be provided as it becomes available. This means it is expected that more information on the immune response and how long it lasts will become available in coming months.

After you receive 1 dose of the Pfizer vaccine, you should have a second dose at least 21 days later to complete the vaccination schedule.

  • You may not be protected against COVID-19 disease until at least 7 days after your second dose.
  • Current data suggests that protection is improved with a second dose.

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 given at least 21 days 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 30 minutes after being given the Pfizer vaccine 
  • If these symptoms develop after that, go straight to the emergency department at your nearest hospital.


  1. Comirnaty COVID-19 vaccine Medsafe Consumer Information, NZ
  2. Comirnaty European Medicines Agency
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 09 Feb 2021