Influenza vaccine

Also called the flu vaccine

Easy-to-read medicine information about the flu vaccine – what is it, when is it given and possible side effects.

What is the flu vaccine?

Influenza vaccine (also called flu vaccine) is used to prevent infection caused by the influenza ("flu") virus. The flu can cause serious illness, especially in young children, the elderly, 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 influenza.

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.

The flu vaccine works by making your immune system produce special cells called antibodies that will attack and kill the flu virus when it enters your body. This means that if you get infected with the flu these protective antibodies are already in your bloodstream to quickly fight off the germs.

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

Make sure you get vaccinated every year

It’s important to get the flu vaccine every year because protection from the previous vaccination becomes less effective over time and each year the flu vaccine is developed to match the different strains of flu virus you are likely to encounter. In New Zealand, you can get your flu vaccine from 1 April each year – you should get the vaccine before winter when the flu is most widespread.

The funded influenza vaccines for 2019
    • For adults and children aged 3 years or older.
    • For children aged under 3 years or 6–35 months. 

Read more about vaccination against influenza

When is the flu vaccine given?

It is possible to come in 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 influenza is just before the start of the winter season – in New Zealand, this would 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.

Pregnant women

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

Who should get the flu vaccine?

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

  • 65 years and over
  • pregnant women (any trimester)
  • under 65 who have certain medical conditions
  • children aged 4 years or under who have been hospitalised for respiratory illness or have a history of significant respiratory illness
  • under 18 living in some regional areas.

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), for those who are in close contact with people with weakened immune systems who may be less able to fight off the flu or who are at high risk of complications from the flu. Frontline healthcare workers usually have the vaccine funded by their employer.

Who should not get the flu vaccine?

The flu vaccine may not be suitable or need to be delayed for people receiving any of the following four cancer treatments:

  • atezolizumab (TECENTRIQ®)
  • ipilimumab (YERVOY®)
  • nivolumab (OPDIVO®)
  • pembrolizumab (KEYTRUDA®)

These are the only four cancer treatments in New Zealand that require influenza vaccination to be delayed. Please contact the person’s oncologist or 0800 IMMUNE (0800 466 863) for current advice about influenza vaccination for these people BEFORE administering the vaccine.

If you have a fever your doctor may recommend postponing the vaccination until you are well.

If you have had a severe allergic reaction or Guillain Baree Syndrome following the flu vaccine in the past, let your doctor know before having another flu vaccination.


The vaccine is given by injection into the 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 required to achieve protection for the season.

Children aged between 6 months and under 9 years: two doses of the vaccine are required, with the second dose given at least 4 weeks after the first. Children in this age group who have received an influenza vaccine at any time in the past require only one dose.

What about side effects?

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
  • It 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, use a fan.
  • 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.
  • It usually settles 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 the face, lips, mouth or have problems breathing
  • Allergic reactions to influenza vaccine are very rare.
  • If you develop these signs within a few days of the immunisation, tell your doctor immediately or ring HealthLine 0800 611 116.

Where can I get vaccinated?

The best place to go for vaccinations is your family medical clinic. They have your medical records and can check to see if you’ve already had a particular vaccination. Either your doctor or a nurse can give the vaccination.

If you don’t have a family doctor, you can go to one of the after-hour medical clinics. Ring them first to make sure they can help you with the vaccination you need.

You can find a clinic near you on the Healthpoint website. Put in your address and region, and under Select a service, click on GPs/Accident & Urgent Medical Care.

Vaccines on the National Immunisation Schedule are free. Other vaccines are funded only for people at particular risk of disease. You can choose to pay for vaccines that you are not eligible to receive for free.

Learn more

The following links have more information on the influenza vaccine. 

Frequently asked questions about the flu vaccine 
Flu can be anywhere FightFlu, Ministry of Health NZ  


  1. Everything you need to know about flu 2019 The Immunisation Advisory Centre
  2. Influenza vaccines The Immunisation Advisory Centre
  3. Influenza Immunization Handbook New Zealand 2017
  4. Vaccine administration - overview The Immunisation Advisory Centre
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 28 Mar 2019