U.S. Requiring Controversial Vaccine

The vaccine from Merck is Gardasil, the drugmaker's bestseller. GlaxoSmithKline's (GSK Quote) Cervarix, a rival treatment, is not available in the U.S. because it is still under evaluation by the Food and Drug Administration. Cervarix, however, is licensed in 64 other countries.

Gardasil, approved by the FDA in June 2006, is designed to be effective against four of about 100 types of HPV, two of which are responsible for the development of approximately 72% of cervical cancers in the U.S. Worldwide sales of Merck vaccines totaled $995 million in the second quarter, with Gardasil accounting for about a third of the amount.

Some medical experts have expressed concern about the vaccinations. It's not clear how long the vaccination will be effective or whether a booster shot will be needed, they say. At the same time, there is a lack of information about the vaccination's effectiveness when combined with other immunizations. The National Vaccine Information Center has warned about the possibility of adverse reactions to Gardasil, saying the CDC has assumed, but not tested, whether combining Gardasil with other vaccinations is safe.

More than 20 states, including Virginia and Texas, backed down from plans, supported by Merck, to make the vaccines mandatory for their residents after the CDC and citizens groups fomented opposition. Parents and medical experts grew concerned about the safety of the vaccine, the perceived encouragement of sexual activity by young people, removal of choice, and the appropriateness and benefits. Texas refused to approve the governor's executive order to mandate vaccination, and Virginia and Washington, D.C., have opt-out clauses.