A large number of infections with anal cancer-associated strains of human papillomavirus (HPV) among older gay men could be prevented with the use of HPV vaccines, Australian research presented to the recent 7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Kuala Lumpur shows.
HIV-positive men were especially likely to have anal infection with a high-risk strain of HPV at baseline and to have incident infections over three years of follow-up.
Investigators from the Study of the Prevention of Anal Cancer (SPANC) in Sydney undertook the research because of the high prevalence of anal HPV infection among gay men, especially those infected with HIV.
Persistent infection with a high-risk strain of HPV can lead to anal cell changes that can lead to cancer. The rate of anal cancer is especially high among HIV-positive gay men at 100 cases per 100,000.
The quadrivalent HPV vaccine (qHPV, Gardasil) provides a high degree of protection against infection with HPV types 6, 11, 16 and 18; types 6 and 11 are associated with genital warts and types 16 and 18 with anal and genital cancers. In Australia, the vaccine has been recommended for school-age girls since 2007 and for boys since 2013. The vaccine is approved for women up to the age of 45 and recommended only for men aged 26 and under, due to a lack of data in older male populations.
A nonavalent HPV vaccine (nHPV) is currently being developed by Merck & Co. This is designed to provide protection against a broader spectrum of HPV genotypes including HPV 6, 11, 16, 18, 31, 33, 45, 52 and 58.
Investigators wanted to establish the potential impact of vaccination with qHPV or nHPV on the incidence of anal HPV infection among older gay men. They especially wanted to see if HIV infection and age were risk factors for infection with high-risk strains of HPV.
Full text of article available at link below –