Vaccines against cervical cancer show protection

Two vaccine companies, Merck & Co. and GlaxoSmithKline (GSK), are racing to get approval for their vaccines against human papillomavirus (HPV). HPV is transmitted sexually and causes genital warts in men and women, and can cause cervical cancer in women. About 99% of all cases of cervical cancer are caused by HPV. Fifty percent of cervical cancers are from a virus strain called HPV 16, while another 25% are from HPV 18. A vaccine that protects against HPV 16, 18, and other strains is likely to nearly eliminate cervical cancer if widely distributed to uninfected women.

In October researchers from Merck reported that their vaccine against HPV 16 protected 94% of vaccinated women against infection. Merck is developing another version of the vaccine that will protect against HPV 18 and other strains.

GSK’s HPV vaccine covers the two major HPV strains, 16 and 18. In clinical trials the vaccine gave women 100% protection against infection with these two strains.

More than half a million women worldwide are diagnosed with cervical cancer each year, and every year nearly 300,000 women die of this cancer. In most of the world cervical cancer screening is not done on a regular basis. A multi-strain HPV vaccine given before a girl becomes sexually active should prevent her from becoming infected with HPV. It is still likely to be a few years before an HPV vaccine is on the market.