A vaccine that promises protection against a common female cancer—what could possibly be controversial about that? Plenty, if the vaccine in question targets a sexually transmitted infection that causes 70% of cervical cancers and, to be most effective, should be given to girls as young as 10 before they become sexually active.1

The vaccine is Merck's Gardasil, which protects against four strains of human papillomavirus: types 16 and 18, responsible for 70% of all cervical cancers, and types 6 and 11, which cause 90% of cases of genital warts.1 Three injections provide protection for at least five years, but the vaccine is expensive at about $360 (£185; €280) a shot.

The vaccine is undoubtedly set to be a blockbuster product for Merck. Twenty US states are considering bills that would make the immunisation a requirement for school attendance, which could net Merck billions of dollars.2 With a rival vaccine (Cervarix) from GlaxosmithKline due to be approved in the next year, Merck has been engaged in some heavy lobbying of its product (www.gardasil.com). Health freedom organisations, among other critics, have condemned Merck's “strong arm” marketing methods, claiming the company hopes to use profits from Gardasil to fund the huge litigation costs it has had to pay over rofecoxib (Vioxx).3 And last week the vaccine made front page news in the United Kingdom with a Guardian story questioning Merck's motives in funding a summit on cervical cancer in Paris for doctors and patient organisations.4

Plans for mass vaccination with Gardasil are already well advanced around the world. Approved by the Food and Drug Administration in June 2006, …