Experimental HPV vaccine could boost cervical cancer protection worldwide
A ‘next generation’ vaccine that protects against nine types of human papillomavirus (HPV) may prevent even more cervical cancers than the current immunisation programme, according to an analysis by an international team of researchers.
"New vaccines will have to be properly tested to be sure they are safe and effective before being used" - Jessica Kirby, Cancer Research UK
The new vaccine, currently under investigation by pharmaceutical company Merck, covers nine types of HPV, which between them account for at least 85 per cent of cervical abnormalities that can develop into cancer.
Almost all cases of cervical cancer are caused by HPV infection. But of more than 100 different types of HPV, only around 12 – known as ‘high risk’ types – have been linked to cancer.
The current vaccination programme protects against just two of these: types 16 and 18, which account for around 70 per cent of cervical cancer cases.
The vaccine can prevent the development of cancer itself, and of ‘pre-cancers’ - alterations to cells in the cervix known as ‘cervical intraepithelial neoplasia’, or CIN.
Study leader Dr Elmar A Joura, an associate professor of gynaecology at the Medical University of Vienna in Austria, said the team were interested in understanding the potential for broadening the range of high-risk HPV types covered by the vaccine.
"We wanted to study how many cervical pre-cancers could potentially be prevented by an investigational ... vaccine that provides protection against the HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58," said Joura.
The study, funded by Merck and published in the journal Cancer Epidemiology, Biomarkers & Prevention, looked at data on 12,514 women aged between 15 and 45.
A total of 2,507 were diagnosed with cervical abnormalities – defined as CIN1, 2 or 3 depending on how severe the changes to the cells were.
The researchers calculated that seven of the high-risk HPV types covered by the new vaccine were responsible for about 55 per cent of CIN 1, about 78 per cent of CIN 2, about 91 percent of CIN 3 cases.
The findings suggest that the new vaccine could improve on the already effective vaccination programme, with the potential to prevent around 90 per cent of invasive cervical cancer cases worldwide.
Jessica Kirby, senior health information manager at Cancer Research UK, said: "The current HPV vaccines, which protect against two cancer-causing types of HPV, are already highly effective at preventing cervical abnormalities and cancers, but adding more HPV types into the vaccine should raise this even further.
"New vaccines will have to be properly tested to be sure they are safe and effective before being used, but if they are proved to work, they could help prevent even more cases of cervical cancer in future."
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