Cervarix, a vaccination designed to protect against human papillomavirus (HPV) 16 and 18-believed to be precursors of cervical cancer-has just won approval from the European drugs regulators. Approval in the US is not far behind, expected to be granted next year.
Both vaccines are supposed to be given to girls between 11 and 12 years of age, and are designed to prevent cervical cancer and genital warts in adult life.
GSK claims that Cervarix is an improvement on Merck's Gardasil vaccine. It includes a 'novel' addition that GSK has called 'AS04', which is a combination of aluminium hydroxide and MPL (monophosphoryl lipid A).
In addition to providing protection against the two viruses, Cervarix is also supposed to reduce the chances of an abnormal Pap smear.
So confident is GSK of its new vaccine that it's planning an expensive head-to-head trial with Gardasil, involving 1000 women. The prize is certainly worth winning. Gardasil, which won approval last year, has already earned $723m for Merck in the first half of this year alone, although not all of its customers have been willing ones. Some states in the US have made the vaccine compulsory, causing an outcry among the Religious Right who have regarded the vaccine as a license for sexual relationships outside of marriage.
Parents should perhaps be more worried that Gardasil may also be a killer. So far, three young girls have died after being vaccinated, and 1637 adverse reactions have been reported to America's drugs regulator, the Food and Drug Administration (FDA) (BMJ, 2007; 334: 1182).
Not that the FDA has freely revealed this information. It has been prised from them by campaigning group Judicial Watch, which exercised its powers under America's Freedom of Information legislation.
Similar worries concerning the vaccine have been raised in Australia. At one school, 25 girls given their first HPV shot experienced headache and nausea, and four needed to be sent to hospital.
But there's not just a question mark over the vaccine's safety; there's one over its effectiveness, too (see box below). So, before offering it the laurel wreath out of hand, the Lancet team might have waited for independent verification of the vaccine's efficacy. As it is, most of the people in the study's research team received funding or support from GSK; in fact, the trial was entirely paid for by GSK, and the technical analyses were provided by employees of the drug giant (Lancet, 2004; 364: 1757-65).
While no one is denying that cervical cancer is an awful and deadly disease, it is also one that is making a fast retreat without the aid of any vaccine programme. The cervical cancer rate has declined by 80 per cent in the US over the past 50 years. In fact, its incidence had dropped to 8.5 per cent of every 100,000 women in 2002-four years before Gardasil was even approved-and cervical cancer now represents just 0.7 per cent of all cancer deaths. Doctors believe that the plain and simple cervical (Pap) smear has contributed a great deal in reduc-ing the threat of cervical cancer.
Despite this marked decline in the disease, the drug companies are keen to press their vaccines on young girls, even against their will. And at $360 per three-shot course, it's not difficult to see why.
HPV vaccines: do they work?
The US FDA has been at great pains to stress that Gardasil was approved because of its supposed protective qualities against human papillomavirus (HPV)-16 and -18, and not because it prevents cervical cancer.
But, first of all, not all cases of cervical cancer are caused by these two strains of HPV. Indeed, at least 30 per cent of cases have other causes-and some researchers say that figure may be an underestimate. Although the virus, and especially HPV-16, have been found in up to 70 per cent of cervical cancer cases, it doesn't mean that the virus is the actual cause of the cancer. In one study of 200 women, regardless of whether or not the women were positive for HPV-16, progression of the disease did not vary (Lancet, 1994; 344: 432-5).
Worse, Gardasil hasn't been especially efficient at protecting against HPV anyway. In one trial, 361 women out of 8817 given the vaccine developed precancerous lesions within three years (Obstet Gynecol, 2007; 109: 360-70).
As you'd expect, GSK claims that its own vaccine, Cervarix, is far more effective than Gardasil. Certainly, its progress through the clinical-trials process has been garnering adulatory headlines as it goes. It so caught the eye of the editorial team at The Lancet medical journal during early-phase trials that it devoted its front cover to the vaccine. In very large print, it announced that the vaccine "could contribute substantially to reducing worldwide rates of cervical cancer".
At that stage, Cervarix was still code-named 'HPV-16 and HPV-18'. As such, it was tested on 1113 women, and proved to be effective against infection in nearly 92 per cent of cases (Lancet, 2004; 364: 1757-65).