Critics who believe HPV vaccine can trigger suicidal thoughts damage attempts to protect girls against cervical cancer
Three years ago, two teenage girls from rural villages in the Indian state of Andhra Pradesh consumed poison and killed themselves. Neither knew the other; they lived some 37 miles apart, and there was a five-month gap between their deaths. The only obvious connection between these suicides was the method: the pair swallowed pesticide, the availability of which makes it the most commonly used suicide method among girls in rural India.
Yet these two tragedies have become inexorably entwined, capturing public attention, as did the deaths of five other girls – one of whom drowned, another who was bitten by a snake and another with malaria. These unrelated deaths have been used by anti-vaccine campaigners in the country to undermine a medicine that protects girls from cervical cancer.
The supposed link between these deaths was the fact that several weeks prior, or in some cases months, the girls had received a vaccine to protect them against human papillomavirus (HPV), the most common cause of cervical cancer. For anti-inoculation groups this was enough to deem the jab unsafe.
A media and political frenzy ensued and, three years later, HPV vaccines have failed to regain public confidence in India. Even today, a public interest litigation, filed this year against the use of HPV vaccines in India, and a parliamentary panel report, published last month, are claiming these girls' deaths are linked to the jab.
Given that India has the largest number of cervical cancer deaths in the world – with more than 70,000 women and girls, or a quarter of all cases, dying every year – the suspension of this vital vaccine programme will inevitably cost lives.
The problem is not the safety record of HPV vaccines – more than 175m doses have been distributed worldwide, from Nepal and Bhutan to Australia and the US, with the main side effect being fainting. The issue is the culture of blame and the misunderstanding of how vaccines are monitored and evaluated. This is a vital part of establishing vaccine safety and should be encouraged.
Whenever a vaccine is introduced it is important to cast the net wide and study any potentially adverse effects in recipients. This makes it possible to gauge the prevalence of known side effects and to detect any that may not have been apparent during clinical trials. But that does not mean that every so-called adverse event following immunisation (AEFI), is attributable to the vaccine. In the vast majority of cases, the vaccine is ruled out.
This subtle distinction is often lost when reported, and not just in the mainstream media. A recent article published in a medical journal that is subject to peer review, the gold standard of scientific scrutiny, used the terms "died of AEFIs" and "deaths due to AEFIs" when questioning the safety of the five-in-one pentavalent vaccine. The point is that by definition the relationship is temporal and not causal.
That is not to say that vaccines cannot lead to serious adverse reactions. We know, for example, that for every 2-3m administered doses of the oral polio vaccine, one recipient will have a serious adverse reaction.
For the diphtheria-tetanus-pertussis (DTP) vaccine, used routinely throughout the world for decades, serious reactions occur closer to one in every 750,000. Although this can be terrible for those directly affected and their families, the overall benefit of the vaccine – preventing many more deaths and illnesses – balances out a very small number of negative reactions.
In the case of HPV vaccines, critics argue that the vaccine could trigger suicidal thoughts and tendencies, as has been the case with some antidepressants. With more than 175m doses distributed worldwide, suicidal ideation has never before been implicated. Also, the known mechanisms for suicide tend to act on the regulation of serotonin, the mood neurotransmitter, and have nothing to do with the immune system.
But perhaps the most compelling evidence is that the suicide rate for girls in southern India is one of the highest in the world, with about 32 of every 100,000 girls killing themselves. With tens of thousands of teenage girls receiving the HPV vaccine, it would have been unusual if none of them went on to kill themselves.
Anti-vaccine sentiment is not really to blame here; it may even have a small role to play in keeping vaccine safety systems in check. The media and politicians should not be allowed to get away with conveniently ignoring context and fact to pursue their own agenda.
We saw this 30 years ago in the US with the Vaccine Roulette documentary on the diphtheria-pertussis-tetanus jab; we also saw it in the UK with the reporting of Andrew Wakefield's theories about the MMR vaccine.
Now with HPV and pentavalent vaccines, the same story is unfolding in India. This is the country with the largest number of unimmunised children in the world, where new vaccines could make a huge positive difference on mortality, morbidity and healthcare costs.
But it is not just a worry for India. With HPV vaccine programmes just beginning in eight low-income countries, ill-informed and dangerous comments by a handful of opponents and journalists threaten the lives of millions of children the world over.
Dr Seth Berkley is chief executive of the Gavi Alliance, a public-private partnership focused on saving children's lives and protecting people's health by increasing access to immunisation in poor countries.
HPV vaccine
Vaccines and immunisation
Cervical cancer
India
Health
theguardian.com © 2013 Guardian News and Media Limited or its affiliated companies. All rights reserved. | Use of this content is subject to our Terms & Conditions | More Feeds