UK researchers report that their initial tests on a new vaccine targeting a virus associated with a number of cancers is proving effective.
They say they recorded a heightened immune response to cancer cells infected with Epstein Barr virus (EBV).
The study, by the University of Birmingham and the Royal Marsden Hospital, was presented at the National Cancer Research Institute conference.
The virus usually causes no health problems, but is associated with a number of cancers, including lymphomas and naso-pharyngeal carcinoma.
In these cases - which are particularly common in the Far East and Africa - the cells in the tumour are infected with the virus.
The new vaccine targets two proteins (EBNA1 and LMP2) that appear in cancer cells infected with the virus.
Researcher Dr Neil Steven said: "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.
"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."
The researchers are currently recruiting patients with EBV positive tumours who have already received chemotherapy, and who have no other treatment option.
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 said it was likely that the vaccine would be used in conjunction with chemotherapy - possibly to prevent the re-growth or spread of disease linked to the virus.
He said: "Cancer vaccines do have tremendous potential for future clinical use."