The vaccine, called Gardasil, guards against cancer and genital warts caused by the human papillomavirus, the most common sexually transmitted disease. It is the culmination of a 15-year effort that began at the National Cancer Institute and a research center in Australia, and health officials described the vaccine as a landmark.

Federal vaccine experts are widely expected to recommend that all 11-to-12-year-old girls get the vaccine, but its reach could be limited by its high price and religious objections to its use. Merck, Gardasil’s maker, said a full, three-shot course would cost $360, making Gardasil among the most expensive vaccines ever made.

“This is a huge advance,” said Dr Jesse Goodman, director of the Food and Drug Administration’s biologics center. “It demonstrates that vaccines can work beyond childhood diseases to protect the health of adults.”

The vaccine prevents lasting infections with two human papilloma virus strains that cause 70 per cent of cancers and another two strains that cause 90 per cent of genital warts. But if girls have already been exposed to those strains, the vaccine has no effect, so health experts want the vaccine given before girls have sex. The median age at which girls have sex is 15.

A Merck spokeswoman said Gardasil, which was approved for girls and women ages 9 to 26, would be available in doctors’ offices by the end of June.

The vaccine is not approved for use in boys, although Merck hopes one day to change that. If the company is successful, analysts expect that sales could surpass $4 billion by 2010.

Cervical cancer is the second-leading cause of death in women across the globe, affecting an estimated 470,000 women and killing 233,000 each year. Widespread use of Pap smears has reduced its toll in richer nations. In the US, about 9,710 women contract cervical cancer each year, and some 3,700 die. Private health insurers are likely to cover the vaccine for 11-to-12-year-old girls, although older women may have to pay for it themselves. GlaxoSmithKline, based in London, is also developing a vaccine against cervical cancer that it expects to submit for FDA approval at the end of the year.

In India, you have to wait, tests on

• Vaccine-maker Merck has tied up with ICMR to conduct trials in India

• Trials to start in 2 months, first one to take a yr, follow-up to take four years

• But doctors say cancer medicines are usually available in India soon after they are available in the West; so FDA approval may hasten availablity