ViroBlogy

Human papillomavirus and cervical cancer - copyright Russell Kightley Media

The fact that genital Human papillomaviruses (HPVs) cause cervical cancer in women, as well as a variety of other growths and lesions in both men and women, is not in dispute.  The fact that cervical cancer is a major and growing scourge of women in developing countries is also non-contentious: of the more than 500 000 cases and 300 000 deaths due to the disease every year, more than 80% occur in the developing world.  This is largely because, unlike their counterparts in the developed world, poor Third World women either do not get screened using the relatively simple cytological detection method known as the Papanicolau (Pap) smear, or do not get treated thereafter.  Thus, cervical cancer really is a disease of poverty, given that most deaths occur due to a lack of simple procedures being provided in clinics.

The best method of prevention of an infectious disease is almost always a vaccine: HPV vaccines have been around a while now, and have proved to be both safe and efficacious – both primary requirements of a vaccine.  Both Merck and GlaxoSmithKline’s vaccines – the yeast-produced Gardasil and insect cell-produced Cervarix respectively – are virus-like particles (VLPs) composed of the major HPV coat protein L1 only; Cervarix contains particles of the high-risk HPV types (or species) 16 and 18 and Gardasil contains VLPs derived from HPVs 16 and 18 as well as the genital wart-causing 6 and 11.

The vaccines are both “blockbusters” – that is, they both have sales of over US$1 billion – are are possibly the best-researched human vaccines ever made.  They are also possibly among the most expensive: Gardasil went on sale in the USA at $120 per dose – and a full treatment consists of 3 doses, for a total cost per person treated of $360; Cervarix retails at around the same price.

This is so far beyond the budget of most people in most countries as to be akin to their expectation of winning a lottery – and of the order of 1000x as expensive as possibly the most widely distributed vaccine in the world, which is Bacillus Calmette-Guerin (BCG), the Mycobacterium tuberculosis vaccine.

It is a sad fact of life that the whole WHO Expanded Programme on Immunisation – EPI – six vaccine bundle of polio, measles, neonatal tetanus, diphtheria, pertussis (whooping cough) and tuberculosis vaccines “… costs no more than US$1 … (at UNICEF-discounted prices), and another US$14 for programme costs (laboratories, transport, the cold chain, personnel and research) to fully immunize a child”.  It is also a sad fact that the new generation of vaccines – exemplified by the yeast-made recombinant hepatitis B virus (HBV) subunit vaccine – are expensive even when discounted after patents have expired: thus, HBV vaccine launched at US$150 for three doses in 1986, and came down to around $10 now.  It is included in EPI bundles in some countries because of even greater discounting (down to ~$1); however, its cost is generally greater than the rest of the bundle combined.

So what should happen with HPV vaccines?  How are they going to get to the people who need them most, at the price they can afford – which is nothing?  The simple answer is that governments and international agencies must buy them, as is presently the case with the EPI package – and that they must be very heavily discounted, to allow this.

In fact, at the recent Papillomavirus Conference in July in Montreal (which we should write up in more detail elsewhere), I heard that the Mexican government has managed to secure  HPV vaccine at US$27/dose – or 25% of the regular price – for a campaign they are mounting in some regions to supply vaccine for free.  So it is possible – however, even this price is far too high, as it represents about the per capita per annum public health expenditure in the poorest countries who probably need it most.

It raises my blood pressure, therefore, when I read that in several highly-developed western countries there are a number of controversies (see also here) around HPV vaccination: yet again, on the heels of the measles and MMR (measles-mumps-rubella viruses) vaccines-cause-autism idiocy, people who can afford vaccines are among the most stupid when it comes to having them.

The facts, as opposed to the hype, are these:

• the vaccines were proven to be safe in extended clinical trials
• they were proven to be efficacious in preventing infection and development of precancerous lesions and genital warts – in men as well as in women

Inflammatory stories about deaths due to HPV vaccines are just that – stories.  A recent publication from India, where the government suspended a vaccine study due to deaths of girls involved in the trial, puts things into perspective:

“The causes of death had been scrutinized by the State Government and reported to ICMR and Drugs Controller General of India; all were satisfied that no death was vaccine-related [ my emphasis]. We understand that there is an unusually high frequency of death among girls in this community, which is what deserves immediate enquiry and remedial interventions….
The death of a 14-year old British girl shortly after receiving HPV Vaccine,evoked considerable media attention across the world. The necropsy studies showed that she had malignant tumor affecting her heart and lungs…. The vaccine was not her cause of death.”

There is also considerable silliness surrounding the vaccination of girls – and, hopefully, boys! – against what is very largely a sexually transmitted virus.

Do people have the same problem with HBV?

Or – is it possible?? – they don’t know that it is also frequently a sexually-transmitted disease, among adults at least?

In any case, the kinds of prudishness-by-proxy that result in non-vaccination against HPV or HBV are simple foolishness.

And I would be happy to tell anyone so.

Meantime, we want to make HPV vaccines in plants. Any sponsors??

Tags: cancer, cervical cancer, HPV, HPV vaccine, vaccine controversy, virus

This entry was posted on 28 October, 2010 at 18:46 and is filed under General Virology, Vaccines: General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.