Human papillomavirus, or HPV, is extremely common amongst sexually active people and a highly publicised programme is currently under way to immunise young women. If immunisation of these women reaches a sufficiently high level their male sex partners will also be protected by a process known as 'herd immunity"
But men who have sex with men will not be protected and researchers are building a case for young gay men to also be immunised. A group of infections disease experts has recommended that medications funding body Pharmac make vaccinations available to all males aged 11 to 18 to ensure gay men are covered. HPV immunisation for gay men has been a subject at this week's New Zealand Immunisation Conference.
"HPV vaccination is an incredibly important and timely issue for gay and bisexual men in New Zealand," says HIV researcher Dr Peter Saxton.
He believes public health opinion on HPV vaccination is slowly shifting in favour of gay men. "Not long ago a widespread assumption was that sexually active gay men would gain little benefit from being vaccinated because of the rapid early acquisition of various HPV strains."
Saxton says that HPV is the world's most common STI, it is especially common in gay male sexual networks, and transmission occurs relatively easily."Although exposure to at least one HPV strain does occur quickly among gay men, overseas studies show that only some gay men appear to have persistent infection with HPV 16, the strain most strongly causally associated with anal cancer. Very few will have been exposed to all the HPV strains that the Gardasil vaccine protects against (HPV6, 11, 16 and 18). This means almost all sexually active gay men will get at least some benefit from HPV vaccination, and some will gain a lot - it's a situation of 'high burden, high benefit'. "
"That said, ideally vaccination should occur before gay men have their first sexual encounter," Saxton says, "which is why vaccinating all males at ages 11-12 may eventually be necessary for greatest impact."
"HPV infection and its consequences are avoidable for the first time. That's far better than doing nothing, waiting, then treating disease.
Dr Nikki Turner of the Immunisation Advisory Centre has pointed to the success of an HPV immunisation programme for young males in Australia. "It's been dramatically successful over there," Dr Turner says. "They've seen a dramatic reduction in genital warts."
Turner believes the reason New Zealand has yet to follow Australia's lead is based on the cost of the programme. Pharmac says its three-year review of immunisations will result in any changes to the national pharmaceutical schedule being made by July next year.