Research published on bmj.com today suggests that including boys in human papillomavirus (HPV) vaccination programmes of pre-adolescent girls would not be cost-effective provided there is high vaccine coverage in girls. An accompanying BMJ editorial concludes 'the best policy is to ensure that preadolescent females are vaccinated worldwide'.
According to the BMJ, previous studies have consistently shown that HPV vaccination of pre-adolescent (12 year-old) girls provides good value for money. (HPV causes cervical cancer.) Because HPV infections are sexually transmitted, vaccinating boys will likely provide direct health benefits to the boys themselves — reducing the risks of genital warts, anal cancer and penis cancer (already very rare) - as well as indirect health benefits to their sexual partners by reducing transmission.
The question the Harvard School of Public Health in Boston tries to answer in their research is whether or not these benefits are worth the investment. Researchers conducted a cost-effectiveness analysis to compare HPV vaccination of pre-adolescent girls alone with vaccination of both pre-adolescent girls and boys in the US.
The study used models that take into account the dynamics of HPV infection and cervical cancer screening strategies to predict the health benefits and economic costs of programmes by combining epidemiological, clinical, and demographic information from the US population.
The researchers also examined how alternative scenarios might impact on cost-effectiveness, varying assumptions regarding screening practice, vaccine efficacy in boys, duration of vaccine protection, and long-term impact on health outcomes not yet observed in clinical trials such as anal and oral cancers.
The units used for measuring cost-effectiveness are QALYs - quality-adjusted life year. An intervention is considered good value for money if it costs less than $100,000 per QALY.
By this criteria, HPV vaccination of pre-adolescent girls (with continued screening in adulthood) is good value for money. Assuming 75% vaccination coverage and lifelong vaccine protection, routine vaccination of 12-year-old girls was consistently found to be less than $50,000 per QALY gained, compared with screening alone.
However, including boys in the routine vaccination programme pushed the cost-effectiveness up to over $100,000 per QALY, even when assuming high vaccine protection and health benefits.
'Our results suggest that if vaccine coverage and efficacy are high among pre-adolescent girls, including boys in an HPV programme is unlikely to provide comparatively good value for resources,' say the authors.
They also point out that more than 80% of the 500,000 annual cases of cervical cancer occur in so-called 'low resource settings' - mainly developing countries which cannot afford or access HPV vaccines. Targeting young women in these populations for HPV vaccination and screening older women would therefore have a bigger effect on reducing the burden of cervical cancer than widespread HPV vaccination of young men from resource rich areas.
Rejecting the HPV vaccine for boys, the BMJ editorial by Philip E Castle and Isabel Scarinci says 'Advocacy for male HPV vaccination is also made on ethical grounds: to promote equality and social responsibility in both sexes. However, consistent use of condoms can partially protect against HPV and provide cheap protection against all sexually transmitted infections, including HIV, as well as unwanted pregnancy. Vaginally applied microbicides are another promising way of preventing HPV infections and other sexually transmitted diseases.'
Meanwhile the Alliance for Natural Health is today calling for an independent inquiry into the safety of the HPV vaccine used in the UK, Cervarix, manufactured by GlaxoSmithKline. They believe Cervarix is implicated in several cases of disability in girls given the vaccine.
In a surprising change of position, Dr Diane Harper of the University of Missouri, who was directly involved in the clinical trials of the HPV vaccine used in the USA, Gardasil, and a paid consultant to the manufacturers Merck, recently questioned the wisdom of a vaccination programme on CBS News.
Previously on the MHF and malehealth websites:
Page created on October 9th, 2009
Page updated on August 12th, 2010