Last week health officials in the U.S. reported a dramatic 50% decline in human papillomavirus (HPV) infections in teenagers between 2003 and 2010. The sharp reduction was credited to vaccination with the HPV vaccine, which was introduced in 2006. However, the size of the decline was unexpected, in view of the poor response to recommendations that girls get vaccinated at ages 11 or 12. (Since HPV is a sexually-transmitted infection it is crucial to reach girls well before the onset of sexual activity). Only 30% of girls in that age group have received all 3 doses of the vaccine, which protects against the main cancer-causing types of the virus.
These positive results highlight the urgency of making the vaccine available in the developing world, where it is most needed because that is where 85% of the half million new cases of cervical cancer each year occur, and because most women do not receive routine gynecologic exams and Pap smears. Fully 88% of the estimated 275,000 annual deaths from cervical cancer worldwide occur in developing countries. Africa and South Asia have the highest rates -- between 4 and 6 times those in the U.S.
Furthermore, the number of new cases of cervical cancer in Asia is projected to increase by between 50 and 100% by 2025.
In the past 5 years, there has been a groundswell of international activity by the World Health Organization, NGOs like the GAVI Alliance, philanthropies, local governments, and the pharmaceutical industry to target the largely avoidable mortality from this disease. Programs range from low-cost screening for cervical cancer to vaccination programs.
However, the serious challenges confronting grass-roots programs targeting women and a sexually-transmitted disease in populations with low literacy and other vulnerabilities are not to be under-estimated.
The recent experience of a pilot study in India provides a cautionary tale of how things can go badly wrong and can set back the cause of improving the health of these populations.
In 2007 a study funded by the Bill and Melinda Gates Foundation and run by the international health philanthropy
The trial created an uproar in May, 2011 when it was revealed in a report by the ICMR that 7 girls had died after receiving the vaccine. Although there was no indication that the deaths were caused by the vaccine, the deaths drew attention to an inadequate infrastructure for monitoring possible adverse effects as well as failures to obtain informed consent.
Last week, I spoke with Dr. Purnima Madhivanan, a professor at Florida International University, who has conducted a study of the acceptability of the HPV vaccine in Mysore, India. She emphasized how badly the cause of HPV vaccination in India has been set back by the poorly-prepared and poorly-monitored Gates Foundation-sponsored trial.
She went further, asserting that in India no value is placed on the lives of women. Therefore, if HPV vaccination is defined as an issue that is pertinent only to women, it stands little chance of gaining support and resources in a country with many other urgent problems.
She argues compellingly that HPV vaccination needs to be defined as a serious issue for both sexes. HPV-related cancers in males include oropharyngeal, penile, and anal cancers. As with cervical cancer in women, it is believed that the majority of these cancers caused by HPV infection could be prevented by vaccination before the onset of sexual activity. Furthermore, vaccinating both girls and boys is essential to reducing the spread of the virus in the population. (HPV vaccination has been approved for girls and boys in the U.S. by the FDA).
Treating HPV infection as something that is best treated at the population level is likely to offer the most efficient and cost-effective way to curtail the spread of the infection and to save lives in a country lacking in local medical services and screening capabilities. This has been the approach adopted by the Indian government to the prevention of primary liver cancer caused by hepatitis B virus (HBV), as well as other infectious diseases.
Because the two available HPV vaccines do not protect against all HPV types, they will not prevent all cases of cervical or other HPV-associated cancers. According to the CDC, about 30% of cervical cancers will not be prevented by the vaccines, so there is a need to improve access to screening for cervical cancer in developing countries. And progress is being made on this front.
Given the attitude of distrust toward foreign NGOs, pharmaceutical companies, and the biotech industry in many developing countries, demonstration projects need to be carefully designed and tailored to the culture and literacy level of the local population, and scrupulously monitored for adherence to the highest ethical standards.
Of course, this is no easy task. But the alternative is that the goal of greatly reducing preventable mortality could be subverted by the kind of distrust of vaccination that arose in the UK and elsewhere in the West as a result of the erroneous, but highly publicized, linking of vaccination with the measles, mumps, and rubella vaccine to autism.
Geoffrey Kabat is a cancer epidemiologist at the Albert Einstein College of Medicine and author of Hyping Health Risks: Environmental Hazards in Everyday Life and the Science of Epidemiology.
