Sexual health experts are calling for what has until now been known as a cervical cancer vaccine to be state-funded for boys as well as girls.
The Government pays for girls to be given Gardasil because it protects against the types of the sexually transmitted infection HPV (human papilloma virus) that cause 70 per cent of cervical cancer.
But it can also protect women and men against other, less common HPV-linked cancers of the genital-anal area, and against the HPV types that cause 90 per cent of genital warts.
Warts are far less serious than cancer, but still distressing for patients and often require prolonged health care.
Australian researchers wrote this month in a medical journal of the "near disappearance" of genital warts in young women four years after the start of Australia's HPV vaccination campaign.
Auckland Sexual Health Service doctors Jeannie Oliphant and Nicky Perkins wrote in the NZ Medical Journal that New Zealand's offer of free vaccination to girls and young women from 2008 had led to a reduction in the number of new, young, female clients who had genital warts from 14 per cent to 5 per cent.
They attributed Auckland's smaller reduction than in a Melbourne study to New Zealand's lower uptake of thevaccine.
They also found there may have been a reduction in warts among young men probably because of women having had the vaccine.
The Melbourne study found a reduction of genital wart diagnosis among heterosexual men, but not homosexual men.
Dr Oliphant and Dr Perkins suggested that extending the New Zealand vaccination programme to all boys in year 8 at school was the strategy most likely to provide protection for men who had sex with men, as selective vaccination "would require young men to identify their sexuality to health care providers preferably before initiation of sexual activity".
Gardasil supplier CSL Biotherapies said a US study showed the vaccine helped prevent males developing some pre-cancers, cancers and other disease.
And an influential body advising the US Centres for Disease Control and Prevention has recommended that boys aged 11 and 12 be routinely vaccinated with Gardasil.
Auckland gynaecologist Professor Ron Jones yesterday urged the NZ Government to extend Gardasil funding to boys.
Health Ministry immunisation manager David Wansbrough said the ministry was not considering extending the free-vaccination programme to boys, but parents could pay privately to have their sons vaccinated.
* Gardasil vaccination - approved for females aged 9-45, males 9-15
* Best given before children become sexually active
* Year 8 girls can have the three injections state-funded at participating schools
* Or at medical centres and most family planning clinics
* Women born 1990-91 have until December 31 to start the free vaccination
* Cost is about $500 for boys and non-funded women
* 45 per cent of eligible females have had the full course