Cancer vaccines are a type of biological therapy. Research in this area is at an early stage and vaccines are mainly available as part of clinical trials.
What vaccines are
Vaccines can help to protect us from infection and the diseases it can cause. They can also be used to treat and prevent some types of cancer.
Vaccines deliver tiny amounts of proteins into the body. Depending on the vaccine, these proteins might come from viruses, bacteria or cancer cells but they are not capable of causing disease.
The body's immune system recognises the vaccine proteins and sets up an attack against them.
White blood cells make proteins called antibodies that can recognise particular proteins in the vaccine. The antibodies stick to the vaccine proteins and help to remove them from the body.
Some of the antibodies stay in the body though. So if you are exposed to the same proteins again in the future, the body recognises them and starts making the right antibodies straight away. This can be enough to prevent the infection altogether.
Cancer vaccines help the immune system to recognise and attack cancer cells.
Vaccines to prevent cancer
There is currently only one vaccine to prevent cancer available.
It can prevent cancer of the neck of the womb (cervix) by protecting against infection with the human papilloma virus (HPV). This virus is known to cause changes that can lead to cancer of the cervix.
If women have vaccinations before they have been exposed to the HPV virus, they have a much lower risk of cervical cancer.
The UK has a programme which offers the cervical cancer vaccine to all girls aged 12 and 13.
There are many clinical trials underway using vaccines to try to prevent other cancers, but this is still early research.
Vaccines to treat cancer
Vaccines that treat cancer are designed to try and get the immune system to recognise and attack cancer cells. They may:
- stop further growth of a cancer
- prevent a cancer from coming back
- destroy any cancer cells left behind after other treatments
Different types of cancer vaccine
Scientists are studying many different types of cancer vaccines and how they work in different ways. More research is needed before they have a full picture of how well this type of treatment works and which cancers it may treat.
The following types of cancer vaccines are most commonly under investigation throughout the world:
These vaccines are made from special proteins (antigens) in cancer cells. They aim to stimulate your immune system to attack the cancer. Scientists have worked out the genetic codes of many cancer cell proteins, so they can make them in the lab in large quantities.
Whole cell vaccines
A whole cell vaccine uses the whole cancer cell, not just a specific cell protein (antigen), to make the vaccine. Scientists make the vaccine from your own cancer cells, another person’s cancer cells or cancer cells that were grown in the laboratory.
Dendritic cell vaccines
Dendritic cells help the immune system recognise and attack abnormal cells, such as cancer cells. To make the vaccine, scientists grow dendritic cells alongside cancer cells in the lab. The vaccine then stimulates your immune system to attack the cancer.
These vaccines are made with bits of DNA from cancer cells. They can be injected into the body to make the cells of the immune system better at responding to and destroying cancer cells.
Anti idiotype vaccines
This vaccine stimulates the body to make antibodies against cancer cells.