Decorative image

Flu vaccine and cancer treatment

Cancer or its treatment can lower your resistance to infection and make you more likely to catch flu. Find out more about the flu vaccine.

Cancer and immunity

Cancer or its treatment can lower your resistance to infection. Doctors call this immunosuppression or being immunocompromised. You may be more at risk of catching flu (influenza) if this applies to you.

If you do get flu and have low immunity you are more likely to become very ill and get complications such as chest infections (pneumonia).

The flu vaccination

Flu (influenza) is an infection caused by a virus. It is very infectious. You mainly catch it from coughs and sneezes of people who have the virus. The symptoms of flu often come on very quickly and include: 

  • a high temperature (fever)
  • aching muscles
  • a cough
  • headaches

Anyone who has flu feels pretty awful but most healthy people recover within a few days, as their immune system gets rid of the virus. Occasionally people develop complications, such as severe chest infections. These are serious illnesses which can need hospital treatment. A small number of people die due to the complications.

The flu vaccination makes it less likely that you will catch flu. If you have had the vaccine and do get flu you are likely to recover more quickly and are less likely to get complications.

Adults have the vaccination as a small injection under the skin. Children usually have a nasal spray vaccine.

The flu virus changes, so each year you need to have the vaccine again to protect yourself against the most common type of flu predicted for that year.

Who should have the flu vaccination

Some cancer treatments lower immunity and lower your resistance to flu. These include:

  • chemotherapy
  • radiotherapy
  • some targeted cancer drugs
  • some immunotherapy treatments
  • long term steroids
  • removal of the spleen

Your doctor will usually suggest that you have the flu vaccine if you have low immunity due to cancer or its treatment. But check with them first. 

After cancer treatment your resistance to infection might be low for some months or years.

Is the vaccine safe?


The flu vaccine injection doesn't contain live flu virus so you won’t develop flu from having it. It is safe to have it while you are having cancer treatment.

But you shouldn’t have the flu vaccine and check with your doctor if you:

  • are allergic to egg (the vaccine is made from hen’s eggs)
  • have had a reaction to a vaccine before


Some pre school and primary school children have the flu vaccine as a nasal spray. Talk to your medical team if your child has cancer. Your doctor may recommend that your child doesn’t have the nasal spray if their immune system is severely weakened.

The nasal spray contains a live, but weakened form of the flu vaccine. So there is a very small chance that the virus could be passed to your child. The doctor might suggest your child has the flu vaccine injection instead.

Side effects of the flu vaccine

The vaccine doesn’t usually cause many side effects. But with the injection you may have:

  • slight soreness around the injection site
  • a slight fever and aching joints (which doesn’t lead to flu)

Possible side effects of the nasal spray include:

  • runny or blocked nose
  • headache
  • tiredness
  • loss of appetite

How you get the flu vaccination

It's important to have the vaccination before the flu virus starts to circulate in the population. This is most likely to happen during the winter months. So vaccination clinics usually start running in late September and continue through to mid November. You can contact your GP to find out about clinic times.

If you are in the middle of cancer drug treatment, you should talk to your cancer specialist about the best time to have the vaccination. Your immune system is weaker when you are having some cancer drug treatments, which means the vaccine may not work quite so well. Your specialist will tell you when it is best to have the injection to get the greatest chance of protection from flu.

The flu vaccination is free to people who are at increased risk of catching flu.

Other vaccinations

Your doctor might suggest that you have the pneumococcal vaccine if your immunity is low. And if you're travelling, you might need to have other vaccinations.

Pneumococcal vaccine

The pneumococcal vaccine is also called the pneumo jab. The pneumococcal virus causes pneumonia, meningitis and septicaemia. Although these are not common infections, they can be very serious. So people who have low immunity should also have this vaccine.

Things to know about the pneumococcal vaccine:

  • most people only need to have it once – it protects you for life
  • if you have had your spleen removed (a splenectomy) you may need to have the vaccination repeated after 3 to 5 years – check with your doctor
  • you should have the vaccine at least 2 weeks before starting any treatment that affects your immune system (such as chemotherapy)
  • wait at least 3 months after cancer treatment finishes before having the pneumococcal vaccination
  • it is available all year round

Travel vaccinations

Contact with other people who have the flu vaccine


It is generally safe for you to be in contact with adults who have had the flu vaccine as an injection. 


Some pre school and primary school children have the flu vaccine as a nasal spray. You should avoid close contact with children who have had the nasal spray for 2 weeks following their vaccination if your immune system is severely weakened.

The nasal spray contains a live, but weakened form of the flu vaccine. So there is a very small chance that the vaccine virus could be passed on to you.  The injection does not contain a live form, so these precautions do not apply to contact with people who have had the injection.

Check with your doctor if you are unsure whether your cancer or its treatment means that your immune system is weakened.

Information and help

Dangoor sponsorship

About Cancer generously supported by Dangoor Education since 2010.