Professor Harald zur Hausan told the ECCO cancer conference in Lisbon on Monday that one in 10 cancers might never develop if vaccines are fully developed - and delivered to every country that needs them.

We currently have 10m cases of cancer a year worldwide. On that basis, it should be possible in the future to prevent around 1.25m of them

Professor Harald zur Hausen

Already, a vaccine against the virus thought to cause the vast majority of cervical cancer cases works well in animals, and appears to be safe and produce an immune response in humans.

Other viruses seem to play a role in the development of liver cancer and some lymphomas.

However, the latest research targets the human papillomavirus, implicated in cervical cancer.

In human volunteers, antibodies against HPV were 10-times higher following vaccination than after natural HPV infection.

Ahead by a nose

However, potentially one of the most significant advances is the possibility of a vaccine deliverable via a nasal spray rather than requiring injection by a trained medical worker.

One project is trying to carry the viral fragments which should trigger the immune response within another virus, called a parvovirus. Protection from HPV would be conferred by getting infected with the parvovirus.

Professor Harald zur Hausen, chairman of the managing board of the German Cancer Research Centre in Heidelberg, said: "This would be particularly suitable for tropical countries.

"If we can perfect these vaccines and apply them globally, then preventing infection by the most prevalent high-risk types of HPV could, in theory, prevent more than 300,000 cancer cases a year."

Overall, he said, the prospects for successful anti-cancer vaccines were promising. "We currently have 10m cases of cancer a year worldwide. On that basis, it should be possible in the future to prevent around 1.25m of them through vaccination.