Merck & Co. will donate cervical cancer vaccine to inoculate 1 million women in some of the world's poorest countries.
Merck announced the gift Wednesday at the third annual Clinton Global Initiative conference in New York.
The company said at least 3 million doses of Gardasil are to be distributed over the next five years. The vaccine is given in three shots, spread over six months.
Cervical cancer, caused by a sexually transmitted virus, is the No. 2 cause of cancer deaths worldwide, with nearly 500,000 new cases and 250,000 deaths each year. Most deaths occur in poor nations, where women rarely get tests to detect cervical cancer early, when it is most curable.
Merck plans to partner with a nongovernment organization to set up programs to distribute the vaccine in countries yet to be chosen.
"Our company is fully committed to making Gardasil available to those who need it," Margaret McGlynn, head of Merck Vaccines and Infections Diseases, said in a statement.
Gardasil targets four strains of the human papilloma virus and is 99 percent effective in preventing infection by two strains that together cause about 70 of cervical cancer cases. It is nearly as effective in blocking two other strains that cause genital warts but not cancer.
New data shows Gardasil is partially effective in blocking 10 other cancer-causing strains.
In the United States, Gardasil costs about $360 (255 EUR) for three doses, plus any fee for a doctor visit.
Doctors stress that even with vaccination, women still need regular Pap tests. Many doctors also urge women to get a separate HPV test, which can detect the HPV virus before problems are detected with a Pap smear.
Merck has the only cervical cancer vaccine approved in the United States, but rival GlaxoSmithKline's vaccine, Cervarix, was approved Monday for sale in the 27 European Union member states and is awaiting U.S. approval.