Influenza vaccine

The influenza vaccine is used to prevent infection caused by the influenza (flu) virus. Find out about the vaccine and possible side effects.

On this page, you will find information about:

Also see common questions about the flu vaccine.

Influenza vaccine for 2021

Flu vaccine for 2021
  • The 2021 Influenza Immunisation Programme starts on 14 April 2021 for people aged 65 and over.
  • The programme for people aged under 65 years is due to begin on 17 May.
  • The programme runs to 31 December 2021. All groups can be vaccinated until then.
  • For a list of who is eligible for the free flu vaccine for 2021, see the eligibility criteria.
Pfizer COVID-19 vaccine and the flu vaccine
  • The flu vaccine does not protect against COVID-19. However, it will help prevent the flu, a serious illness that causes hundreds of deaths each winter in New Zealand. 
  • The flu vaccine can be given at the same time or immediately before or after the COVID-19 vaccine. If given at the same time, you will receive the vaccines at separate places on your arms and with different syringes. Read more about about COVID-19 vaccine and flu vaccine.

What is the flu vaccine?

The influenza vaccine (also called the flu vaccine) is used to prevent infection caused by the influenza (flu) virus. The flu can cause serious illness, especially in young children, older adults and people with chronic health problems, but anyone can become seriously ill from the flu virus. Even if you are not feeling sick, you could still be infected with the flu virus and pass it on to others. Read more about the flu.

Vaccination is the best way to prevent infection and reduce the seriousness of illness if you become infected. It will greatly improve your chances of not getting the flu, but it does not give 100% protection.

Being vaccinated causes your body to produce antibodies against the flu virus. This means your body can respond faster and more effectively to the flu. By first coming across a non-infectious version of the virus in the vaccine, it learns to recognise it. When it comes across it again, your body can react much faster and in a more effective way.

Even if you get the flu after being vaccinated, you usually get a mild form of it and recover faster, and are less likely to have serious complications.

Why do I need to get vaccinated every year?

You need to get the flu vaccine every year because protection from the previous vaccination becomes less effective over time. Each year the influenza viruses can change. The strains in the vaccine usually change each year in response to the changing virus pattern. Read more about vaccination against influenza

When is the flu vaccine given?

It is possible to come into contact with flu viruses all year round, but the chance of the flu virus circulating in the community is highest during winter. For most people, the best time to be vaccinated against the flu is just before the start of the winter season. In New Zealand, this is between April and June. It takes 2 weeks after vaccination for the vaccine to be fully effective. You may still get the flu in this time if you come into contact with the virus, so get it done early in time for winter.


If you become pregnant after winter and have not received the current flu vaccine, it is recommended that you have it by 31 December.

Who should get the flu vaccine?

Anyone over the age of 6 months can have the flu vaccine. The flu vaccine is free for these people, who are considered to be at greater risk of complications from the flu:

  • pregnant women (any trimester)
  • people aged 65 years and over
  • people under 65 years of age with with certain chronic conditions, such as chronic heart disease, chronic liver disease, diabetes, cancer, asthma and COPD
  • children aged 4 years or under who have been in hospital for respiratory illness or have a history of significant respiratory illness, including children aged 6–59 months (under 5 years) who were hospitalised with measles.

Check with your doctor if you are uncertain about whether you qualify for a free flu vaccine. Read more about the eligibility criteria.

The vaccination is also recommended (although may not be free) if you are in close contact with people with weakened immune systems, as these people may be less able to fight off the flu or are at high risk of complications from it. Frontline healthcare workers usually have the vaccine funded by their employer.

Who should not get the flu vaccine?

If you have had a severe allergic reaction following the flu vaccine in the past, let your doctor know before having another flu vaccination. Also, if you have a fever or are unwell, your doctor may recommend postponing the vaccination until you are well.

How is the flu vaccine given?

The vaccine is given by injection into a muscle, such as the muscle on your upper arm. If you have a condition that makes you bleed more easily than normal, it may be given as an injection underneath your skin. Babies and toddlers are given the injection on the side of their thigh.

Adults and children 9 years and older: Only one dose of the vaccine is needed to get protection for the season.

Children aged between 6 months and under 9 years: Two doses of the vaccine are needed, with the second dose given at least 4 weeks after the first. Children in this age group who have received a flu vaccine at any time in the past need only one dose.

After you get the flu vaccine, a trained healthcare professional will keep an eye on you for at least 20 minutes afterwards to make sure you don't have any reaction to the vaccination.

What are the side effects of influenza vaccine?

Like all medicines, the flu vaccine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Pain, swelling or redness around the injection site 
  • This is quite common after having the vaccination.
  • It usually starts a few hours after getting the injection and settles within a few days.
  • Place a cold, wet cloth or ice pack where the injection was given. Leave it on for a short time. 
  • Do not rub the injection site.
  • Tell your doctor if troublesome.
  • Read more: After your immunisation
  • Fever
  • This is quite common for the first 1 or 2 days after receiving the injection and usually settles within a few days.
  • Dress lightly, with a single layer of clothing.
  • Do not wrap your child in a blanket.
  • Keep the room cool and use a fan if you have one.
  • Drink plenty of fluids.
  • The routine use of paracetamol is not recommended following vaccinations, but may be used if your child is miserable or distressed.
  • Tell your doctor if the fever persists.
  • Read more: After your immunisation
  • Feeling unwell, tired or weak
  • Loss of appetite
  • Muscle ache
  • Headache
  • These are quite common for the first 1 or 2 days after receiving the injection.
  • They usually settle within a few days.
  • Rest and drink plenty of fluids.
  • The routine use of paracetamol is not recommended following vaccinations, but may be used for relief of severe discomfort.
  • Tell your doctor if troublesome.
  • Read more: After your immunisation
  • Signs of an allergic reaction such as skin rash, itching, blisters, peeling skin, swelling of your face, lips, mouth or problems breathing
  • Allergic reactions to the flu vaccine are very rare.
  • If you develop these signs within a few days of the vaccination, tell your doctor immediately or call Healthline free on 0800 611 116.

Where can I get vaccinated?

People eligible for a free flu vaccine
Eligible people can get a free vaccination from their family doctor/general practice. It is usually the practice nurse who gives the vaccine. Many community pharmacies provide free flu vaccinations to people aged 13 years and older and pregnant women (any trimester).
People who are not eligible to receive a free flu vaccine
The flu vaccination is available from:

Please contact your healthcare provider about the cost of getting the flu vaccine.

Learn more

The following links have more information on the flu vaccine:

Frequently asked questions about the flu vaccine 
Flu can be anywhere FightFlu, Ministry of Health, NZ
Influenza (flu) topics Health Navigator NZ


  1. 2021 influenza vaccines The Immunisation Advisory Centre, NZ
  2. Influenza vaccines The Immunisation Advisory Centre, NZ
  3. Vaccine administration – overview The Immunisation Advisory Centre, NZ
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 28 Mar 2019