A vaccine that could prevent young women from developing most cases of cervical cancer could be on the market within a few years.

Researchers are testing dozens of vaccines against different types of cancer but those that protect women against strains of the human papillomavirus (HPV), which are linked to more than 70 percent of cervical cancer cases, are the most advanced.

“I believe there will be an HPV vaccine sometime in the next few years,” Anne Szarewski, a clinical consultant at Britain’s Wolfson Institute of Preventative Medicine, told journalists.

Results from early trials of two separate vaccines developed by drugs giant GlaxoSmithKline and Merck, which protect against HPV infection, have been promising.

HPV is sexually transmitted. More than 75 percent of women are infected with HPV at some time during their lives. It usually lasts for a short time and produces no symptoms.

But in some women it can progress to cervical cancer, one of the most common cancers in women. Each year 470,000 women around the world are diagnosed with the disease and 230,000, mostly in the developing world, die, according to the International Agency for Research on Cancer (IARC) in Lyon, France.

There are more than 100 types of HPV virus, but HPV 16 and 18 are linked to the majority of cervical cancers.

“We don’t know how long the immunity will last,” said Szarewski. “We hope it will deliver lifetime protection against cervical cancer.”

ENORMOUS POTENTIAL

Developed countries have screening programs to detect early signs of cervical cancer, which has a good cure rate if it is diagnosed early.

Szarewski said an HPV vaccine would have enormous potential in poor countries where screening is not available.

She is beginning phase III trials of one of the vaccines in 300 women between 15 and 25 years old. The women will be given three doses of the HPV vaccine or a hepatitis A vaccine, which will act as the control.

The HPV vaccines are two of many cancer vaccines in development or trials. Scientists are testing different approaches to weaken cancer cell resistance and to boost various types of immune system cells to fight the disease.

They are studying very rare cases of spontaneous cancer remission, to determine what happens in the body to kill the tumour and are also vaccinating bone marrow donors to see whether the cells they donate to cancer patients act like a vaccine.

Professor Peter Johnson of Southampton General Hospital in southern England, believes a combination of approaches may be needed to boost the immune system against cancer. “In the next 5 to 10 years we will see more of these vaccines coming into the clinic,” he said.