What you need to know about the AstraZeneca vaccine

If you are 18 years of age or older and either you cannot get the Pfizer vaccine or you want a different option, you can get the AstraZeneca vaccine.

About the AstraZeneca vaccine

The AstraZeneca COVID-19 vaccine is available for anyone aged 18 years and older who either wants a different option or if you cannot get the Pfizer vaccine.

Pfizer is the preferred COVID-19 vaccine for use in New Zealand. Both the Pfizer and AstraZeneca vaccines will protect you against the symptoms of COVID-19. Both vaccines are free.

The AstraZeneca vaccine needs 2 doses. You will need to wait at least 4 weeks before getting your second dose. To have the best protection, you need to get both doses of the vaccine.

The AstraZeneca vaccine has been thoroughly assessed for safety by Medsafe. Medsafe only grants approval for using a vaccine in Aotearoa once it is satisfied the international evidence shows benefits outweigh the risks. There have been no shortcuts taken in granting approval. The AstraZeneca vaccine has been used successfully by millions worldwide.

Getting your AstraZeneca vaccine

You should not get the AstraZeneca vaccine if you:

  • have had a severe allergic reaction to this vaccine or its ingredients
  • have had a major blood clot at the same time as having low levels of platelets (thrombocytopenia) after receiving any COVID-19 vaccine 
  • have had Capillary Leak Syndrome (CLS – a condition causing fluid leakage from small blood vessels).

You cannot get the AstraZeneca vaccine if you are under 18 years old.

The AstraZeneca vaccine is injected into a muscle (usually in the upper arm). The second injection can be given between 4 and 12 weeks after the first injection. If you get AstraZeneca for the first dose then you should also get it (and not the Pfizer vaccine) for the second dose.

You will need to stay for at least 15 minutes after your vaccination.


There is insufficient data on the use of AstraZeneca in pregnant people, so Pfizer remains the preferred choice of vaccine for this group.

Talk to your doctor about whether the AstraZeneca vaccine is suitable for you if you are pregnant or breastfeeding, or if you think you may be pregnant.

Pregnancy and the Pfizer vaccine

How the AstraZeneca vaccine protects you from COVID-19

The type of coronavirus that causes COVID-19 is new to humans. This is why our bodies do not already know how to fight it off.

The AstraZeneca vaccine stimulates the body’s immune system. It causes the body to produce antibodies to help fight the virus. This will help to protect you against COVID-19 in the future. None of the ingredients in this vaccine can cause COVID-19.

How we know the AstraZeneca vaccine is effective

COVID-19 vaccines are already the most well-studied vaccines ever made.

In the clinical trials, the AstraZeneca vaccine gave 81% protection against the symptoms of COVID-19.

It also shows effectiveness against hospital admission of at least 80% after a single dose.

For the best protection, you need 2 doses.

Side effects

As with all medicines, you might experience some mild side effects. This is common, and a sign that your body is learning to fight the virus.

Side effects of COVID-19 vaccines

Serious side effects

There are some side effects that are very rare but are more serious.

Blood clots are a very rare side effect of the AstraZeneca vaccine. It has occurred in around 1 in 100,000 people who have received the AstraZeneca vaccine.

Symptoms can include:

  • shortness of breath
  • chest pain
  • leg swelling
  • pain in arms or legs
  • severe or persistent headache
  • blurred vision
  • confusion or seizures (fits)
  • abdominal pain.

Very rare cases of Capillary Leak Syndrome (CLS) have been reported. The symptoms of this condition include rapid swelling of the arms and legs, sudden weight gain and feeling faint.

Very rare cases of Guillain-Barré syndrome (GBS) have also been reported. GBS is a rare immune disorder that causes nerve inflammation. Symptoms may include pain, numbness and muscle weakness in the arms and legs which may progress to the chest and face. 

If you experience any of these symptoms, seek medical attention immediately.

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