Posts Tagged ‘vaccines’
By: Danielle Daee
Human papillomavirus (HPV) is an important health issue because it is the most common and recurrent sexually transmitted infection worldwide and it can cause genital warts and cancer (including cervical, anal, oral, and penile cancers). While many of these cancers are rare, cervical cancer remains one of the leading causes of cancer mortality in women worldwide. Current screening procedures for cervical cancer are very successful in identifying precancerous lesions in women; however, regular screenings remain rare in impoverished populations. As a result, there has been a push for the development of an HPV vaccine to combat the challenges of HPV infections.
Merck recently developed an efficacious, quadrivalent vaccine (Gardasil) that prevents infection by HPV strains 16 and 18 (which cause ~70% of cervical and anal cancers) and HPV strains 6 and 11 (which cause 90% of genital warts) in both men and women. Although universal vaccination would have clear benefits for both sexes and would help achieve herd immunity, the development of vaccination programs has been stymied by costs. Currently, to be effective a three-dose regimen ($120 per dose) is required. This is particularly cost-prohibitive for target, impoverished populations worldwide. Furthermore, the vaccine will only prevent ~70% of cancers so additional screening procedures will still be necessary for effective cancer detection, driving preventative costs even higher.
Although HPV vaccines are clearly effective and important, it is evident that current costs will prevent the widespread use of the vaccines. Moving forward, it is necessary to develop a more cost-effective vaccine by reducing dosage and increasing efficacy. Research efforts should be focused on identifying common peptide targets that could enhance the cross-reactivity of HPV vaccines so numerous variants could be simultaneously targeted. Additionally, it is imperative that scientists and physicians vociferously support the preventative value of an HPV vaccination program. Strong support is essential to persuade international health organizations and local insurance companies that the value (in terms of both cost and human life) is worth the effort to provide affordable and convenient prevention for at-risk individuals.