Researchers at Birmingham University have unravelled important biological "clues" that could lead to the development of vaccines against cervical cancer.

A study, carried out by Cancer Research UK scientists, examined how the body's immune system responds to the human papilloma virus (HPV) - a major cause of the disease.

Scientists studied 41 women, each at different stages of progression from infection to cervical cancer and measured their immune system's response to various proteins. It revealed patients who are able to clear the infection have a different immune response to those in which the virus leads to cervical cancer.

Their findings will enable scientists narrow down which proteins potential vaccines should target to trigger the response that clears HPV infection - and stops the cancer from developing.

Cervical cancer is the second most common female cancer worldwide, with more than half a million new cases are diagnosed every year and causing more than 274,000 deaths.

Dr Jane Steele, of the university's Institute for Cancer Studies, said: "We've now found the patients with precancerous lesions are most likely to develop cervical cancer showed less immune activity from a population of immune cells called helper T cells than the women who were at much less risk.

"This could mean that helper T cells, which play a central role in the immune response, are critical in disease progression."

There are more than 70 different strains of HPV but researchers focused on HPV 16 which is present in up to 70 per cent of cervical cancers.