Experts tell Sharon Ní Chonchúir everything you need to know about the virus and its vaccine.
A large study of Danish and Swedish women has found the human papillomavirus (HPV) vaccination is not linked with 44 serious chronic diseases.
The findings of the study of more than 3mn women were published last week in the Journal of Internal Medicine.
The research brings a new level of reassurance to parents concerned about their schoolgoing daughters getting the HPV vaccination. Here we address key questions about human papillomavirus, a virus that so widespread that four in every five of us will be infected by it at some point in our lives.
What exactly is HPV?
“It’s a virus that has been around for thousands of years, affecting every species on the planet,” says Professor Gráinne Flannelly, consultant obstetrician and gynaecologist and clinical director of CervicalCheck, the national cervical screening programme.
It doesn’t matter if you’re male or female. If you have ever engaged in sexual contact, you were probably exposed to HPV. According to the HSE’s Health Protection Surveillance Centre, about 80% of sexually-active individuals are infected with at least one strain of HPV by the age of 50, with peak incidence of HPV infection occurring in young adults between the ages of 16 and 23.
The infection rates are getting worse. “Whether it’s because of more people being sexually active or because we’re getting better at identifying HPV infection, there is more of it,” says Donal Buggy, the head of services and advocacy for the Irish Cancer Society.
Is infection a cause for concern?
Not necessarily, according to Buggy. “The thing is that most of us contract low-risk forms of the virus which means we live happily oblivious to the fact that we’ve got it at all,” he says.
There are more than 100 different forms of HPV, most of which cause no symptoms and disappear within two years. However, some strains cause more serious problems if they
are left untreated, ranging from genital warts to cancers of the cervix, genitals, anus, head, neck, mouth and throat.
Prof Flannelly explains further. “Some people are more prone to persistent HPV infection. Some of those people then go on to develop pre-cancer and cancer.”
How many people develop HPV-related cancers?
According to the National Cancer Registry of Ireland, an average of 538 HPV-related cancers was diagnosed every year during the period from 2010 to 2014.
Cervical cancer was the most common, accounting for 292 cases out of 538. Throat cancer was the next most common, at 133 cases. There were also 38 cases of cancer of the vulva, 36 of cancer of the anus and rectum, 32 of cancer of the penis and 10 of cancer of the vagina.
“We are also seeing more cases of young people with HPV-related head and neck cancers,” adds Professor Flannelly.
“These cancers are traditionally associated with older people who smoke and drink a lot
but these people are young professionals who go to the gym. Something is clearly changing.”
How is HPV transmitted?
“Mostly, it’s through sexual activity,” says Buggy. “It passes from one person to another through sexual contact so easily that the only way to be sure of avoiding it is to abstain from sexual activity entirely.”
This ease of transmission makes HPV difficult to control. So does the fact that it is resistant to treatment. There is no cure and doctors can only treat the symptoms. Warts, for example, can be removed.
What can we do to protect ourselves from the most dangerous forms of the virus?
Because cervical cancer is the cancer most commonly caused by HPV, this is where smear tests come in. These are offered for free to all women who are or have been sexually active and they involve checking the cells of the cervix for HPV.
If high-risk HPV is found, a more detailed examination called a colposcopy is carried out to check for pre-cancerous cells, which then have to be surgically removed.
This is not an uncommon occurrence. One in 10 Irish women will need invasive treatment to remove these pre-cancerous cells.
Why are we talking about HPV now?
We’ve known about the link between HPV and cancer since the 1980s, when the German virologist Harold zur Hausen discovered that HPV-11, HPV-16 and HPV-18 were to be found in 93% of all cervical cancer samples.
The reason we’re talking about HPV is because there is now a vaccine available. Gardasil4 has been administered free of charge to girls in first year at secondary school since 2010. It provides protection against HPV-16 and HPV-18.
The vaccine is most effective if it’s given before the body encounters HPV. This means before sexual activity occurs. This is why it’s commonly given to young girls but it can also be given to adults up to the age of 26.
The vaccine can also be given to boys, something the Irish Cancer Society hopes will happen in Ireland.
“HPV causes more cancer in females but you achieve a herd effect if you vaccinate the entire population,” says Buggy.
“The boys protect the girls from contracting the virus and vice versa.
Also, the vaccine may be licenced for cervical cancer but it also vaccinates against HPV cancers that affect boys so it protects them too by default. We hope plans will be announced to vaccinate boys very soon.”
What about the anti-vaccine movement?
Both Buggy and Prof Flannelly are dismayed by this. Following claims that hundreds of girls suffered ill health as a result of the Gardasil4 vaccine, vaccination rates have fallen from a high of 87% in 2015 to under 50% at the moment.
230,000 girls have received the vaccine to date and there have been 1099 reports of adverse reactions. More than 80% of those involved short-term issues such as fainting and rashes.
However, anti-vaccine groups claim that some girls have been left seriously ill, suffering from conditions such as chronic fatigue and ME.
Medical professionals see no link between these conditions and the vaccine.
“These conditions have been around for years and there is no higher incidence in girls who have been vaccinated,” says Prof Flannelly.
The research proves this. More than 200m doses of Gardasil4 have been distributed worldwide and in 2015, the European Medicines Agency carried out a review of the vaccine which found no evidence that it was linked to chronic
Buggy finds it upsetting that parents are choosing not to vaccinate their children.
“It’s distressing that these conditions are being linked to a vaccine that could prevent 300 women a year in Ireland from contracting cervical cancer and 90 of them from dying from it,” he says.
“HPV is such a widespread virus but we now have a way of protecting against the worst of it. Just think: the likes of polio and smallpox decimated our populations 100 years ago but vaccinations got rid of them and increased our life expectancy in the process. We could do the same with HPV.”
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