Health economists estimate that depending on how they are used, the two cervical cancer vaccines will cost society $30,000 to $70,000, or higher, for each year of life they save in developed countries  a cost commonly seen in treating people already suffering from deadly cancers. That number will be far higher if a booster is needed.

Looked at another way, countries that pay for the vaccines will have less money available for other health needs. “This kind of money could be better used to solve so many other problems in women’s health,” said Dr. Lippman at McGill. “Some of our provinces are running out of money to provide primary care. I’m not against vaccines, but in Canada and the U.S., women are not dying in the streets of cervical cancer.”

By contrast, if the vaccine were to become cheap enough to be used in the developing world, particularly Africa, it would revolutionize women’s health. Charities like the Global Alliance for Vaccine and Immunizations, backed by the Bill & Melinda Gates Foundation, are trying to devise a solution.

The vaccines offer partial protection against infection from human papillomavirus, or HPV, a common and generally benign sexually transmitted virus that can in rare cases cause cancer after years of silent infection. The Merck vaccine also prevents some genital warts that are caused by other strains of the virus.

In Britain, “this initiative was seen as a good use of resources that fits with the government’s health priorities and political priorities,” said Professor David Salisbury, who heads the Department of Health’s Vaccine and Immunization Committee.

But critics urge restraint. “There is no need to rush,” said Angela Raffle, a specialist in cervical cancer screening with the National Health Service in Britain, where 400 people die of the cancer each year. “If we do this quickly and badly, we could cause more deaths,” from side effects, for example, or from giving girls false security that they are protected for life and no longer need to be screened, Ms. Raffle said.

The Campaigns

Stephanie Levi decided to give her two daughters the vaccine in late 2006 after receiving a newsletter from their physician. “When you get a letter saying this is what you need to do to protect your girls, of course you do it,” she said, adding that she was curious because she had not realized cervical cancer was a problem.