09 Mar 2011
Men can be vaccinated against virus that causes genital warts
MEN in Singapore aged between nine and 26 can now be vaccinated against the human papillomavirus (HPV) as protection against genital warts.
Such warts may put them at risk of cancers of the penis and anus, which can arise from more than 10 different HPV strains.
Up till now, HPV has been more widely known to cause cervical cancer in women. Vaccines have been available to women aged nine to 26 since 2006, to protect them against this cancer.
The Health Sciences Authority (HSA), Singapore's drug regulator, gave the green light last December for men to be given the vaccine Gardasil, based on clinical studies submitted by drug manufacturer Merck Sharpe & Dohme.
Gardasil is one of two HPV vaccines given to women here to prevent cervical cancer, the other being Cervarix.
With this move to make Gardasil available to men, Singapore joins countries such as the United States and Australia.
An HSA spokesman, however, said that whether men should be vaccinated will depend on the clinical assessment of their doctors.
A Ministry of Health (MOH) spokesman said it had no plans to promote the vaccine among men because the cancer link in them is not yet well-established.
Men who want the vaccine can ask for it at clinics where it is available, including some family clinics. It costs $450 to $600 for a three-shot dose. The duration of its effectiveness is not known, and neither has the need for booster shots been established.
Genital warts are one of the most common sexually transmitted infections (STIs) in Singapore and worldwide. In 2009, more than 1,000 cases were reported here, with eight in 10 patients being men.
People with these warts get slow-growing growths on and around their genitals, which may then spread to form painful, cauliflower-shaped clusters. More than 90 per cent of genital warts stem from HPV, of which there are more than 100 types. Some, like Types 16 and 18, can lead to cervical cancer; others, like Types 6 and 11, cause genital warts.
Singapore General Hospital's Associate Professor Tay Sun Kuie, an obstetrician and gynaecologist who has done more than 25 years of research into HPV, said that in most cases, the sexually transmitted HPV exists without developing into genital warts, and only in rare, complicated cases do cancers arise.
Nonetheless, doctors who were contacted generally backed the move to make the vaccine available to men.
Cancer surgeon Gopal Iyer of the National Cancer Centre said the vaccine could reduce the likelihood of Aids, because those with genital warts are at greater risk of other STIs.
Dr Priya Sen, deputy head of the STI control department at the National Skin Centre, said the vaccine is recommended for high-risk groups, such as men who have sex with other men and uninfected men whose female partners are infected with HPV. Ideally, one should be vaccinated before one's first sexual experience, she added.
Madam K. Martens, 42, signed up her 12-year-old son for the vaccine last month, as she was concerned that he, on the verge of puberty, could get infected with HPV in the future.
Last month, it was reported that American researchers said HPV spread by oral sex could be behind the rise in oral cancers among Caucasian men.
But the MOH spokesman said: "There is little direct evidence that HPV vaccination protects against oral or anal cancer."
He noted that a closer look at the study revealed that only 8 per cent of male patients with HPV had Types 16 and 18, the potentially cancer-causing types the vaccine protects against. He further noted that anal and oral cancers are relatively uncommon here, unlike cervical cancer, which ranks sixth among women's cancers here.
Prof Tay agreed, saying that while Gardasil has proven effective in preventing cervical cancer, any suggestion it can do the same for anal or oral cancers would be "extrapolation with no scientific basis".
But gynaecologist Lisa Wong, who practises in Mount Elizabeth Medical Centre, said offering the vaccine to men could indirectly protect women from cervical cancer, given that men may be carriers of cancer-causing HPV Types 16 and 18. Since HPV is spread through sex, it may be best to vaccinate both men and women, she added.
Agreeing, Dr Gopal said: "If most of the population is immunised, the chance of the virus spreading – even among those not immunised – is lowered significantly."
It is why gynaecologist Christopher Ng, who runs a clinic in Camden Medical Centre, believes the vaccine should be extended to men regardless of age, since viral infections are not age-specific.
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Dept of Obstetrics and Gynaecology
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