Pharmaceutical giants Merck and GlaxoSmithKline are gearing up for a bruising showdown with America's religious right after the US medicines regulator approved a new blockbuster cervical cancer vaccine last week.
Conservative groups, including the influential Family Research Council (FRC), have voiced concerns that immunising young girls against the virus that most regularly causes cervical cancer, Human Papilloma- virus, may lead to sexual promiscuity. "We would oppose any measures to legally require vaccination or to coerce parents into authorising it," wrote the FRC in a recent letter to the US government. "Our primary concern is with the message that would be delivered to nine- to 12-year-olds with the administration of the vaccines. Care must be taken not to communicate that such an intervention makes all sex 'safe'."
The Food and Drug Administration's approval of Gardasil, Merck's vaccine, is likely to increase the volume of such complaints ahead of a meeting on 29 June of the Advisory Committee on Immunization Practices. The ACIP is the body that will recommend how, and if, Gardasil should be integrated in the schedule of other mandatory vaccines, such as against polio.
Glaxo filed for registration of its Cervarix vaccine in Europe in March, and expects to file in the US before the year is out. Merck expects approval in Europe later this summer.
Merck and Glaxo have been in discussions with Christian conservative groups in America to assuage their concerns. Lobbying organisations such as the FRC exercise considerable political power, and if they succeed in pushing their agenda it "certainly could have a negative impact" on the use of the vaccine, said Mike Ward, an analyst at Nomura Code Securities.
ACIP's decision will be crucial to the overall penetration of the vaccine in the US, the world's largest drug market. Merck plans to charge $360 (around £200) for the three-jab course given over six months. It estimates that in the US alone there are 32 million females between the ages of nine and 24 - the range for which the FDA approved the vaccine. This equates to $11.5bn.
Ideally, the vaccine should be given at an early age because the Human Papillomavirus it targets is the primary cause of cervical cancer and is passed through sexual contact.
The vaccine does not eliminate the virus in women who are already infected. "For a prophylactic vaccine, it should [be given] before the risk occurs," said Philipe Monteyne, head of Glaxo's vaccines unit.