There is a
“strong” argument for extending UK HPV (human papillomavirus) vaccination
programmes to young gay men, according to an editorial published in the August edition of Sexually Transmitted Infections. The
authors highlight the high incidence of HPV-related anal disease in gay men and
data illustrating the efficacy and cost-effectiveness of vaccination for gay
men aged 26 and younger.
infection with certain high-risk strains of HPV (especially HPV 16 and 18) can
lead to the development of pre-cancerous and cancerous cell changes in the
cervix or anus. Incidence of HPV-associated anal disease is higher among gay
men than any other group. Vaccines have been developed that provide excellent
protection against cancer-associated HPV types.
The vaccines work
best before sexual debut and the HPV vaccine programme in the UK has prioritised
school-aged girls. The theory has been that “herd immunity” would also have
benefits for boys. However, Australia has extended its HPV vaccination scheme to
Despite their high
risk of HPV-associated anal disease, vaccination is not recommended for gay
men in the United Kingdom or elsewhere.
The authors of the
editorial – all of whom are sexual health physicians – argue that this should change. They
show that possible objections to this strategy are baseless.
involving HIV-negative gay men with between one and five sexual partners have
shown that the quadrivalent HPV vaccine (Gardasil,
the product used in the UK school vaccination scheme since 2012) is strongly
immunogenic and is effective at preventing infection, reducing HPV persistence
and preventing the development of external warts. In addition, vaccination was
also shown to reduce rates of pre-cancerous anal lesions. The vaccine was most
effective in people without baseline infection with the HPV types covered by
the vaccine. However, it also had acceptable levels of efficacy in individuals
with evidence of existing HPV 16 or 18 infection.
Other research has
also shown that Gardasil is
immunogenic in HIV-positive gay men. In men with and without baseline HPV 16 or
18 infection, immunisation produced protective antibodies against the four HPV
types covered by the vaccine in at least 98% of people.
There are data
showing that immunisation would be of benefit to the vast majority of sexually
experienced younger gay men.
draw especial attention to a meta-analysis showing that prevalence of anal
infection with HPV 16 and 18 in HIV-negative gay men was 13% and 5%,
respectively. Separate research showed that only 19% of gay men aged 35 and
younger were infected with HPV 16 at baseline. “Seroincidence remained above 3%
per year until age 45 years, illustrating the value of HPV vaccination,” write
Analysis of urine
samples obtained from patients attending sexual health clinics in the UK showed
that prevalence of any high-risk HPV strain was below 5% among gay men aged
under 25, and that fewer than 10% of men in the 24 to 44 age group were infected
with these HPV types.
acknowledge that urine samples can underestimate the prevalence of anal HPV
infection. Nevertheless, they believe the data give “some support to the
hypothesis that a majority of young MSM will be unexposed to HPV 16 or 18”.
US research has
shown that targeted HPV vaccination in younger gay men is cost effective. The
Centers for Disease Control and Prevention now recommends universal vaccination
for boys aged 11 and 12, and vaccination for gay men up to the age of 26.
In 2010, 17,000
gay men aged between 16 and 26 attended a sexual health clinic in the UK, and
the investigators propose that these clinics would provide an ideal host for
the vaccination programme.
vaccination programme would build upon a long-stranding programme of
vaccination of MSM for hepatitis B which has an uptake of 85%,” comment the
“recent data illustrates HPV vaccination of sexually active MSM is effective,
and modelling using conservative analysis suggests vaccination is
cost-effective…the argument for introducing targeted HPV vaccination for MSM up
to age 26 years is strong.”
The UK's Joint Committee on Vaccination and Immunisation will decide whether vaccination of MSM aged 26 and under is cost-effective in 2014 after the completion of age-related prevalence surveys and cost-effectiveness modelling.