An Australian study published by Chow et al in The Lancet Infectious Diseases found a 70% reduction in one type of human papillomavirus (HPV) in gay and bisexual men after the implementation of the school-based HPV vaccination program. The HYPER2 study found that there was a significant reduction in all four vaccine-preventable genotypes in gay/bisexual men aged 16 to 20 years following the introduction of the vaccine for boys in 2013.
Australia is one of the first and few countries that have HPV vaccination programs for both boys and girls. The vaccine covers four HPV genotypes: 6, 11, 16, and 18. Genotypes 6 and 11 cause about 90% of genital wart cases, and genotypes 16 and 18 cause about 70% of cervical and anal cancers.
This is the first study to show that the implementation of a gender-neutral school-based program can reduce high-risk anal HPV and potentially reduce the incidence of anal cancer in gay and bisexual men.
Study Details
This repeated cross-sectional study recruited 400 gay and bisexual men with a median age of 19 years from sexual health clinics and the community in Melbourne.
The results were compared with the HYPER1 group of 200 gay/bisexual men pre-vaccination in 2010 to 2012 and the HYPER2 group of 200 gay/bisexual men postvaccination in 2017 to 2018.
It showed a reduction in anal quadrivalent genotypes from 28% to 7.3%; penile quadrivalent genotypes were also lower in the postvaccination group: 6.1% compared to 11.9%.
Anal cancer incidence has increased globally among men over the last 3 decades. It is overrepresented among gay and bisexual men, particularly those living with human immunodeficiency virus (HIV).
A meta-analysis estimated the incidence of anal cancer to be 45.9 per 100,000 among HIV-positive men who have sex with men. Results from the HYPER2 study suggest that male vaccination may lead to a potential reduction in anal cancer among gay and bisexual men in Australia, which is similar to the reduction in cervical cancer among Australian women after the HPV vaccination program launched in 2007.
“Australia has a very successful HPV vaccination program for both boys and girls, with high vaccine coverage,” said first study author Eric P.F. Chow, PhD. “The vaccine is effective in reducing HPV-related diseases and showing some promising evidence that this may lead to a reduction in HPV-related cancer in the future.”
Disclosure: For full disclosures of the study authors, visit thelancet.com.
