It's just over a year since the HPV vaccination programme was rolled out for 12-year-old girls in Irish secondary schools. Since then, a catch-up programme has been introduced to immunise girls in sixth year of secondary school.
The vaccination programme, along with screening, is anticipated to reduce the number of cervical cancer cases in this country and save many lives in the process.
But it is worth remembering that HPV is not only connected to cervical cancer. It is, after all, called the Human Papillomavirus and affects not just women but men too.
And as there are proven health benefits of the vaccine for men, it begs the question -- why aren't we immunising our teenage boys against HPV also?
It's something that cropped up recently across the water in America. The Centers for Disease Control and Prevention (CDC) is considering recommending the vaccine for boys and will discuss it at a key advisory meeting this month.
In Ireland, there are currently no plans to include teenage boys in the national HPV vaccination programme.
In 2010, the then Minister for Health, Mary Harney, indicated that she would consider introducing the vaccine for boys in the future if its cost were to come down. However the current Department of Health would not say if its position was still in line with Harney's comments.
Its response seems to indicate that it has no plans to introduce the vaccine for boys in the near future.
"International studies and scientific assessments suggest that the best way to prevent most disease due to HPV is to vaccinate as many girls and women as possible," says its statement.
"Routine vaccination is not recommended for boys. According to research carried out by the European Centre for Disease Prevention and Control, the burden of disease associated with HPV Type 16/18 in males is small, as it is related to some anogenital and head and neck cancers and the efficacy of vaccines for the prevention of these relatively rare cancers is not known.
"Following an evaluation of the HPV vaccine in the Irish context, the National Immunisation Advisory Committee recommended that all girls 12 years of age should receive the vaccine."
With the focus on girls and the HPV vaccine, many Irish parents are probably unaware that they can get their son immunised against HPV.
Gardasil is licensed in Europe for boys and men up to 26 years of age (in addition to being licensed for girls and women) and can be provided through a GP (the other HPV vaccine, Cervarix, is not licensed for boys and men). The only setback for parents would be the cost as they would have to pay for the vaccine privately.
There is no vaccination registry in Ireland so it's impossible to determine if there has been any uptake of the vaccine by males in Ireland and, if so, to what extent.
The company that markets Gardasil in Europe, Sanofi Pasteur MSD, doesn't actively target the vaccine towards teenage boys. This is in contrast to the US, where the vaccine holder, Merck, regularly advertises in magazines with the tagline, "Boys can be affected by HPV disease too".
So just how are boys and men affected by HPV?
Some strains of HPV, which is sexually transmitted, are linked to cancers, including cervical cancer in women and cancers of the penis, anus and the oral cavity. There are indications that HPV may have a role to play in other cancers such as tonsil cancer and oesophageal cancer. It's also known that some strains of HPV cause genital warts in males and females.
A study last year in the US found that 50pc of men were infected with the HPV virus over the course of the two-year research. The study, which was published in 'The Lancet' journal, found that each year six per cent of men acquire the cancer-causing strains of HPV, although they don't necessarily go on to develop cancer.
However, there is a strong incidence of genital warts. While not life-threatening, genital warts are not something that anyone wants to get, can be embarrassing and can inhibit someone's sex life.
Vaccinating against HPV could dramatically reduce the number of genital warts cases. Gardasil has an efficacy rate of 89pc in preventing genital warts and 90pc in preventing external genital lesions associated with the virus.
Another reason in favour of boys being vaccinated is that it has a benefit to girls, particularly as there would be less chance of the high-risk HPV 16 and 18 viruses (which cause most cases of cervical cancer) being transmitted to them.
Dr Samantha Hibbits is a senior lecturer at the Department of Obstetrics and Gynaecology in Cardiff University and has a special interest in the area of HPV infection.
"I'm in favour of vaccination of teenage boys alongside the existing HPV vaccination programme in girls," she says.
"HPV is a sexually-transmitted virus and men and women who are sexually active have an equal 80-90pc lifetime risk of infection. High-risk types of the virus are associated with development of pre-cancers and cancers in both genders that includes penile, anal, vagina, vulva and oro-pharyngeal.
"In addition, low-risk HPV infection is linked with genital warts, with a higher incidence reported in men. In order to have successful eradication of the HPV types targeted by the vaccine, it is important to have high coverage in both genders to effectively reduce transmission and increase herd immunity."
The idea of herd immunity is that when a significant portion of the population is vaccinated, it also provides some protection for people who haven't developed immunity or been vaccinated.
Dr Hibbits believes that boys should be included in vaccination programmes.
"Vaccinating boys would have the dual function of protecting them from acquiring HPV and enhancing herd immunity, with the potential to prevent all diseases linked with this virus in the population," she says.
"It is particularly important in regions where HPV vaccine uptake is low and increasing coverage by vaccinating males will also help target hard-to-reach females."
Ireland has a high uptake of the vaccine in girls through the national programme, as opposed to the US, for example, which has lower rates. This is due to a number of factors including state differences in how the vaccine is funded and parental objections to their daughter receiving it.
As of late 2007, only about 25pc of American teenage girls had received at least one of the three HPV vaccinations. Immunising teenage boys could help redress these low rates.
In Ireland the main argument against including boys in a vaccination programme comes down to cost benefit.
Essentially, the number crunchers say that vaccinating boys against the disease works out more costly than the benefits received.
A study by the Harvard School of Public Health in Boston in 2009 found that the HPV vaccination of pre-adolescent girls worked out as good value for money.
However, vaccinating both boys and girls would just fall below the cost-effectiveness threshold.
Dr Shirley McQuade, medical director of the Dublin Well Woman Centre, says: "Healthcare is very much driven by finances and affordability at this stage and economists work out the cost benefits of a treatment or vaccine."
However, Dr McQuade says that if the cost of the vaccine was lowered, then providing a vaccine programme for boys would become less of a debated issue.
"If there was no financial cost involved, it would obviously be advised that everyone get it. Because the vaccine is expensive, it has to be concentrated on where it's going to benefit most and, at the moment, that's women and cervical cancer. But it is worth remembering that the HPV vaccine is just as effective in men and just as safe."
Professor Alf Nicholson, RCSI Professor of Paediatrics and Consultant Paediatrician at Temple Street Children's Hospital, says the jury is still out on whether boys should be routinely vaccinated for HPV.
"To look at it logically, if you're worried about an infection and half the population isn't immunised, it doesn't make sense. But there is obviously the cost effectiveness argument and more research needs to be done -- it's like everything else in life, nobody wants to jump in too early.
"It's a debate that needs to happen at some stage. We know that the vaccine can be used for boys -- it's a question of whether it should be used."
Both Professor Nicholson and Dr Samantha Hibbits mention the rubella vaccine. It was originally given to just females but was later introduced as part of the MMR vaccine for boys and girls. It was also given as a catch-up vaccine to those who were too old for MMR.
"What this example shows is that in the past there have been particular episodes of a single gender-based vaccine programme that was modified to include both genders."
While the government isn't planning a HPV vaccination programme for boys, it is feasible that it could negotiate the cost of the vaccine so that it would become a cost-effective option.
In the meantime, it's up to individual parents to consider whether to have their sons immunised. It could not only help their health, but the health of those they have sexual relations with in the future.