A federal advisory panel Thursday unanimously recommended that the Food and Drug Administration approve a vaccine that has been shown to prevent cervical cancer, the second most prevalent cancer among women worldwide.
The FDA almost always follows the recommendations of its advisory panels and is expected to do so in this case, probably by June 8.
"It is common sense, good medicine and a groundbreaking step forward in the fight against cancer," said Cecile Richards, president of the Planned Parenthood Federation of America.
Conservative Christian groups, which initially raised moral concerns about the vaccine, said they now welcomed it because of its health benefits, but stressed that parents shouldn't be required to have their daughters vaccinated.
Tests in more than 17,000 girls and women have shown that the vaccine, called Gardasil, is nearly 100% effective in blocking cervical cancers caused by the sexually transmitted human papillomavirus.
Gardasil blocks four strains of human papillomavirus. Two strains are thought to be responsible for 70% of the 15,000 cases of cervical cancer diagnosed and the 4,000 deaths caused by it in the United States each year. Worldwide, 400,000 women are diagnosed with cervical cancer each year, and 200,000 die of it. The other two strains it blocks are behind about 50% of genital wart cases.
Human papillomavirus, commonly called HPV, is the most common sexually transmitted disease in this country, with about 20 million people infected.
The vaccine is most effective when given to girls before they become sexually active, which would require administration between the ages of 9 and 13.
Public health groups, nine of whom testified before the panel Thursday morning, were unanimous in recommending approval of the vaccine.
A vaccine utilization committee of the Centers for Disease Control and Prevention is scheduled to meet June 29. It could vote then on whether to recommend universal use of Gardasil in females. A draft proposal recommends vaccinating all girls ages 11 and 12.
Requirements for its use, however, can only be mandated by individual states. In some, including California, such a mandate would require passage of legislation, said Dr. Eileen Yamada of the state Department of Health Services.
Even if it becomes a requirement, added Wendy Wright, president of Concerned Women of America, all states allow children to opt out of mandatory vaccinations for medical or other reasons.
Some conservative religious groups have argued that it may send an implicit message to young girls that sex is OK.
The opposition of such groups was responsible for a recent instance in which the FDA has not followed the recommendation of an advisory committee: A similar panel recommended approval of Plan B, the so-called morning-after pill, in December 2003, but the agency still has not acted.
None of the groups spoke before the panel in opposition, but many representatives indicated they would not have their daughters vaccinated with Gardasil.
"We welcome the vaccine," said Pete Sprigg of the conservative Family Research Council. But, he added, "decisions about sexual health are tied up in personal values, and parents should have the right to transmit personal values to their children."
Parents who know their children do not plan to be sexually active may see no need for the shots, added Linda Klepacki, a spokeswoman for Focus on the Family.
The panel did not consider whether the vaccine should be used in males because there is not yet enough data to support its efficacy. The virus causes rare cases of cancer of the anus and the penis in males, and vaccination of boys would also help prevent its spread among women, experts said.
Dr. Eliav Barr of Merck & Co., the vaccine's manufacturer, said results of studies in males should be available in 2008, at which time the company would seek approval for that group.
Experts expect many women to take the vaccine as well, but it is not recommended for those who might be pregnant because the initial trial found a few birth defects in children of the women who received it.
The panel stressed that Gardasil does not eliminate the need for cervical cancer screening, such as the pap test, because the vaccine does not protect against all HPV strains.
Some experts had reservations about the vaccine that were unrelated to its efficacy or morality: Gardasil is expected to cost as much as $500 and must be administered in three injections over the course of six months.
The cost may put it out of reach for many families of girls at high risk of contracting the virus, and the need for three physician visits could severely limit its use.
"Cost is really going to present public health agencies with a significant challenge," said Dr. Jeffrey Duchin, head of immunizations for the Seattle & King County Public Health Department. The CDC committee could recommend federal subsidies to make Gardasil available to low-income families.
Gardasil was originally developed by Dr. Douglas Lowy of the National Cancer Institute.
If approved, Gardasil would be the second vaccine to protect against cancer. Hepatitis B vaccines have been shown to protect against liver cancer.
GlaxoSmithKline Biological is developing a similar vaccine, called Cervarix, that protects against two strains of the papillomavirus and that has also proved highly effective. The company has said it will seek FDA approval later this year.