Cancer vaccines

Cancer vaccines are a type of cancer treatment that are still in the very early stages of development. Cancer vaccines work by helping the immune system to recognise and fight abnormal cells in the body.

Research is looking at developing different types of cancer vaccines. There are already some vaccines that help to prevent viruses that can cause certain types of cancer. Scientists and doctors are also looking at developing cancer vaccines to help treat different types of cancer, and to stop it coming back after treatment. These may be offered as part of a clinical trial.

Cancer vaccines are usually given as an injection into the skin. This depends on which type of vaccine you have.

If you have any questions about cancer vaccines, talk to your doctor or nurse.

What are vaccines?

Vaccines have been used for many years to prevent infectious illnesses such as flu, tuberculosis (TB) and German measles. Vaccines help the body’s immune system to recognise and fight abnormal cells and substances in the body, such as viruses and bacteria.

Scientists and doctors are trying to develop vaccines that can help the immune system to recognise and destroy cancer cells.

Some vaccines have already been developed for a few types of cancer. These are being tested to see whether they can:

  • prevent certain types of cancer
  • treat some cancers
  • help stop cancer coming back after treatment.

You may be asked to take part in a research trial that includes a new vaccine.

Vaccines to help prevent viruses

Vaccines can be used to prevent viruses that can cause cancer. For example:

  • The HPV (human papilloma virus) vaccine is routinely offered to 12 to 13-year-old girls to prevent HPV. Some strains of HPV can cause cervical cancer.
  • The HBV vaccine is used to prevent hepatitis B, which can cause a type of liver cancer. In the UK, this vaccine is usually only given to people at high risk of developing hepatitis B.

Vaccines to help stop cancer coming back

Some people with early bladder cancer have treatment using the BCG vaccine. The vaccine is put into the bladder. It helps stop early bladder cancers from coming back after surgery.

BCG is not a cancer vaccine. It is a vaccine that was originally developed to prevent tuberculosis.

We have more information about the use of BCG in bladder cancer.

The immune system

Our immune system protects us from infection and disease. It is made up of:

  • the bone marrow
  • the thymus gland (which lies behind the breast bone)
  • the spleen
  • the lymph nodes (also called lymph glands).

Lymphocytes are a type of white blood cell that are made in the bone marrow. They are an important part of our immune system.

There are two types of lymphocytes:

  • B-cells
  • T-cells.

B-cells make special proteins called antibodies. The antibodies react to toxins, bacteria and some cancer cells and stick to these. This allows the T-cells to recognise them as unwanted and together they can destroy them.

Sometimes these harmful substances or cells can hide by growing within the body’s own cells. T-cells can usually sense when the body’s own cells have become abnormal and can destroy them.

The antibodies stay in the body and can recognise anything they have reacted to previously. This means they can act quickly if any of the harmful substances come back.

Cancer and the immune system

The body has lots of ways to detect when cells have become abnormal. When it does detect abnormal cells, it tells the cells to die.

Sometimes the immune system has difficulty recognising that cancer cells are abnormal. This can be for many different reasons. It means the immune system does not know to try to destroy the cancer cells. Because of this, the cells may keep growing.

Having cancer can also lower the immune system. This means it does not work as well as it normally would or can be less effective against cancer cells.

The aim of cancer vaccines

Cancer vaccines are a type of immunotherapy. They can work by:

  • getting the immune system to recognise and target specific cancer cells as abnormal and destroy them
  • boosting the immune system to make it work better (called immune restorers or immune modulators).

How cancer vaccines are made

Cancer vaccines are made from:

  • the person’s own cancer cells
  • someone else’s cancer cells
  • cells grown in a laboratory.

Scientists treat the cancer cells, or proteins from cancer cells, with heat or radiation. This makes sure the cancer cells cannot grow or cause harm when the vaccine is given.

The cancer vaccine contains similar proteins to the cancer cells. This may stimulate the immune system to attack and destroy the cancer cells.

How cancer vaccines are given

Cancer vaccines are usually given as an injection under the skin (subcutaneously). How often they are given depends on the type of cancer and type of vaccine being used. They are often given with other cancer treatment, such as chemotherapy.

Possible side effects of cancer vaccines

The possible side effects of cancer vaccines include:

  • a skin reaction at the injection site
  • a skin rash
  • mild flu-like symptoms.

Certain cancer vaccines may cause more specific symptoms. Your nurse or doctor will talk to you about this. They can also explain how to manage any side effects.

Cancer vaccine research trials

Vaccines are being used in research trials. When a new treatment is being developed, it needs to go through many stages of research called clinical trials.

Cancer vaccines are usually used in trials treating people with advanced cancers that can't be cured. But some research is looking at treating cancers at earlier stages. It is possible that vaccines may be used to try to prevent different types of cancer in the future.

Most of the research into vaccines has looked at treating cancer of the prostate, breast, pancreas, bowel, lung, melanoma, kidney, ovary, bladder, and cervix. Vaccines have also been used to try to treat lymphoma and leukaemia.

The results so far

Cancer vaccines have been researched for many years. Some studies in laboratories have successfully stimulated the immune system. But research has not always been so successful in humans.

Doctors do not fully understand why the previous studies have been unsuccessful. There are a number of theories, including the following:

  • Many people with cancer have reduced immunity. This means their immune systems are not as able to react to the vaccines.
  • Some cancer cells make proteins that stop the immune system from recognising them or attacking them.
  • Cancer cells may be resistant or change to become resistant to the vaccine.

Recent studies have been trying to solve these possible issues. The results have been more encouraging, so there may be more progress in the future.

If you have any questions about cancer vaccines, talk to your doctor or nurse.

Back to Targeted (biological) therapies explained

Cancer growth inhibitors

Cancer growth inhibitors block certain chemical signals within cells, which slows down or stops the growth of the cancer.

Monoclonal antibodies

Monoclonal antibodies can attach themselves to cancer cells to prevent them from growing.