Epstein Barr cancer vaccine: First results

18 Oct 2007

Researchers from the University of Birmingham and the Royal Marsden Hospital are using a vaccination for a common virus as a way of stimulating the body’s immune system to attack cancer cells.

The preliminary results of this trial of vaccination against Epstein Barr Virus (EBV) were recently presented at the National Cancer Research Institute (NCRI) Conference in Birmingham.

The initial results from testing of samples from three patients with EBV positive tumours suggest the vaccine can encourage the body to produce an immune response to cancer cells that are infected with the virus.

Epstein-Barr is a herpes virus that is widespread in all human populations. Although normally the virus causes no health problems it is known to be associated with a number of cancers including lymphomas and naso-pharyngeal carcinoma. This means that cells in these tumours are infected with EBV.

The new vaccine targets two proteins (EBNA1 and LMP2) that are expressed in cancer cells infected with the virus. The vaccine created by the Birmingham team contains a gene made up of elements of EBNA1 and LMP2 which can be recognised by the human immune system. The aim is to boost and redirect an existing immune response to target the cancerous cells that are EBV infected.

If the body is able to produce an immune response to the proteins in the cancer cells it provides a natural mechanism of attacking the disease.

Dr Neil Steven from the University of Birmingham’s Institute for Cancer Studies comments: “Scientists are increasingly looking at ways to use cancer vaccines to stimulate the body’s immune system against tumours.

“EBV is an obvious target because it is present in a number of tumours. In the Far East and Africa, EBV positive tumours like naso-pharyngeal carcinoma and Burkitt’s Lymphoma are very common. In the UK, we see the virus in cancers such as Hodgkin’s disease and nasopharyngeal cancer less frequently. A successful vaccine could have world-wide application building on the benefits of chemotherapy and radiotherapy.

“The initial results of these vaccinations are promising. It seems that the vaccine is able to encourage the body’s immune response to the proteins present in the tumour. The next stage is to assess how effective this process can be in attacking tumours.”

Recruitment is continuing for a trial of the vaccine for patients with EBV positive tumours who have already received chemotherapy or where no alternative treatment exists. A similar study using the same vaccine is currently ongoing in Hong Kong.

Patients receive the vaccination injected into the skin three times at three week intervals. The initial results on samples from three patients showed that injection with the vaccine did stimulate a limited immune response.

Dr Steven continues: “It is likely that in the future an EBV vaccination would be used in conjunction with chemotherapy for many of these tumours to possibly prevent the re-growth or spread of disease linked to the virus.”

Similar research using a genetically modified cold virus is also currently underway at the same institute.