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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 and the pneumococcal 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 an injection into the muscle (intramuscular injection). Children usually have a nasal spray vaccine, although some children might need to have it as an injection..

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 should check with your doctor if you:

  • are allergic to egg (the vaccines are prepared from viruses grown in hen’s eggs)
  • have had a reaction to a vaccine before

People with an egg allergy can have a flu vaccine with a very low egg content. Ask you doctor about this. 


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. This is because the nasal spray contains a live, but weakened form of the flu vaccine.

Normally, the flu vaccine helps a child to build up their immunity to flu. But if your child has a weakened immune system, the immune system may not be strong enough to build up a response. If an immune response is not produced quickly enough, the vaccine virus could cause flu.

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

When to have 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. Or you might be able to have it at your local pharmacist.

It is still worth you having the vaccine after this time if you haven't had it. So check with your cancer specialist.

If you are in the middle of cancer drug treatment, your specialist will probably still recommend that you have the flu vaccine. Ask them about the best time to have it. The vaccine might not give you as much protection as it would a person whose immunity is not low. But it is still important for most people to have it.

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 bacteria causes pneumonia, meningitis and septicaemia. These conditions can be very serious. So people who have low immunity should have a pneumococcal vaccine.

Types of pneumococcal vaccine

There are two different types of pneumococcal vaccine. These are the:

  • pneumococcal polysaccharide vaccine (PPV)
  • pneumococcal conjugate vaccine (PCV)

You should have both vaccines (PCV then PPV 2 months later) if:

  • you have severe low immunity, for example you have acute or chronic leukaemia
  • you are due to have your spleen removed (a splenectomy) or your spleen is not working well
When you have it

The pneumococcal vaccine is available at any time of the year. Check with your doctor when it is best to have it in your situation.

You should ideally have the vaccine at least 2 weeks before having your spleen removed. Or ideally 2 weeks before starting any treatment that affects your immune system, such as chemotherapy.

If you did not a pneumococcal vaccination before treatment, you can have it afterwards. But you should wait at least 3 months after cancer treatment has finished. Check with your specialist about the best time as this might vary depending on your situation. 

For example, leukaemia patients should have PCV from 6 months after chemotherapy. Those who have had a stem cell or bone marrow transplant should have PCV around 9 to 12 months after their transplant. 

You need to have PPV every 5 years if you have had your spleen removed, or your spleen is not working well.

Travel vaccinations

Contact with other people who have the flu vaccine


It is safe for you to be in contact with people 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 and cause flu if your immune system is severely weakened.  

The injection does not contain a live form, so these precautions do not apply to contact with people who have had the injection.

Ask your doctor whether you need to avoid contact with children who have had the nasal spray flu vaccine.

Information and help

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