Most of us think of vaccines as being necessary only for small children and the elderly, or for when we are planning an exotic foreign trip.
But did you know there are also vaccines that can protect you from cancer?
It is an established medical fact that infections from certain viruses can increase a person's likelihood of developing cancer. For example, an infection from the Epstein-Barr virus raises the risk of nose cancer. However, the poster child of this phenomenon has to be the human papillomavirus (HPV), which is the main cause of cervical cancer.
This is why there is a global effort to raise screening rates and vaccinate women and girls against HPV. Here in Singapore, our Health Promotion Board has been working hard to raise awareness of cervical cancer and the need to protect against HPV.
But wait. Since HPV is passed from person to person via intimate contact, surely there must be a vast segment of society that is capable of carrying the virus and transmitting it to women but is being overlooked.
This under-discussed but critical issue is the prevalence of the HPV infection among men.
HPV is an equal opportunity, non-gender biased virus. It infects men just as easily as it infects women.
It is the most common sexually acquired infection in the United States. More than 80 per cent of men and women will acquire a HPV infection by the age of 45, according to an American study.
Fortunately, in most cases, the body is able to spontaneously overcome the HPV infection and it goes away without causing any health problems. However, when the body cannot get rid of the virus, the patient can develop genital warts or even cancer.
The flesh-coloured warts - which grow in the genital and anal area and can affect both men and women - are notoriously stubborn. They require repeated sessions of freezing, laser therapy or even surgery to treat.
I once attended to a patient who had a circumcision to remove multiple warts caused by a HPV infection. Despite this, the warts returned. I finally managed to get rid of them only after multiple sessions of treatments.
In women, HPV infection can cause cervical cancer. However in men, it can lead to some cancers including anal cancer. In fact, HPV is responsible for up to 90 per cent of anal cancers. Although this sounds like a worrying number, anal cancer is itself not a common disease.
In Singapore, cervical cancer is at least 20 times more common than anal cancer. This is perhaps why, to date, much more effort and resources have been dedicated to increasing the awareness of HPV prevention in women, rather than men. This may have contributed to the poor awareness of the disease and its consequences among men.
Another possible explanation for the lack of attention paid to male HPV infection is the fact that most HPV infections do not cause symptoms. This may sound like a good thing, but it also means that men can unknowingly pass the virus to their partners.
Furthermore, HPV is transmitted via intimate skin-to-skin contact so even the correct and consistent use of condoms can't fully protect either partner from getting infected.
There is also no validated screening test for HPV in men. So, even if a man wishes to be responsible towards his partner, he has no access to a commercially available, reliable way to be screened.
This discrepancy in testing availability and awareness can potentially lead to awkward situations. I once attended to a couple. The woman had recently been diagnosed with a HPV infection via a routine cervical cancer screening test.
They came to speak to me about getting her male partner tested. As the conversation developed, it became clear that both parties' intention was to assign blame. But since there was no validated screening test available for the man, the discussion quickly descended into a finger-pointing session. Perhaps this could have been avoided if both of them had been protected against HPV.
Even if our primary goal is only to protect women from HPV-related cervical cancer, raising awareness among young men about their link to HPV is essential in achieving this.
This is best demonstrated by the experience in Australia, where a universal HPV immunisation programme has been in place for girls since 2007. It was extended to include boys in 2013. This has contributed to a significant decrease in the HPV disease burden and is expected to increase HPV herd immunity in Australia.
By 2028, it is predicted that cervical cancer will be classified as a 'rare cancer' in Australia -with four new cases per 100,000 women annually - according to the Lancet Journal.
Evidently, protecting young men against HPV has a double benefit. It shields men from genital warts and cancer, while indirectly protecting their partners.
Today (November 19) is International Men's Day and this year's theme is "men leading by example".
Many men will care deeply about ensuring that their loved ones look after themselves and remain in the best possible health.
There is no better time for men to lead by example by taking care of their own health too.
Speak to a doctor to decide how you can protect yourself and your partner from HPV-related diseases and cancer.
Dr Tan is a general practitioner specialising in men's health. A graduate from the National University of Singapore, he has worked at Tan Tock Seng Hospital and Singapore General Hospital. He currently works at Dr Tan Medical Center.