Cervical cancer vaccine benfits older women -study

*Vaccine provided 91 percent protection against infection

*Potential market for vaccine is large

By Maggie Fox, Health and Science Editor

WASHINGTON, June 1 (Reuters) - Older women can benefit just as much as younger women from Merck's (MRK.N) Gardasil vaccine against cervical cancer, researchers in Colombia reported on Monday.

They found that women ages 24 to 45 who had no history of cancer-causing genital warts or cervical disease were much less likely to become infected with the wart virus if they got the vaccine than women who got placebo jabs.

The study, published in the Lancet medical journal, points to a potentially lucrative new market for the vaccine against the human papilloma virus or HPV.

Merck, which paid for the Colombian study, has also shown that Gardasil is 90 percent effective in preventing sexually transmitted warts in men.

GlaxoSmithKline's (GSK.N) rival vaccine Cervarix protects against two HPV strains and is used in Europe.

Dr. Nubia Munoz of the National Institute of Cancer in Bogota and colleagues tested 1,900 women who got the recommended series of three Gardasil shots and 1,900 who got sham injections.