What is the human papilloma virus, and how does the vaccine work?
03 September 2019

Interview with 

Caroline Cooper, iCASH Cambridge; Graham McKinnon, iCASH Peterborough




From September 2019, boys will be offered the HPV vaccine, as well as girls. To find out more about the virus, how it's tested for, and why the UK vaccine protocol has changed, Chris Smith and Katie Haylor spoke to Cambridge sexual health doctor Caroline Cooper...

Phil - HPV is a group of very common viruses, called the human papilloma viruses. Most HPV infections pass through you without any symptoms, but in some people some viral infections lead to genital warts. A doctor can usually diagnose this by a quick examination, and you can treat them with a cream, or with surgery, or by freezing them. Other HPV infections can be more serious and put you at risk of different types of cancer. Cervical cancer in particular is nearly always due to HPV. Testing for it means a cervical screening. The NHS offers this, by invitation, to all women and people with a cervix aged 25 to 64. There is a vaccine for HPV, and starting in September all schoolchildren aged 12 to 13, no longer just girls, will be offered the vaccine.

Chris - I know that when we first began talking about HPV on this programme, it was in 2005, and we invited Margaret Stanley who was one of the architects of that vaccine, actually here from Cambridge, to come in and tell us about it. People were shocked to learn that cervical cancer is a sexually transmitted disease. Caroline how does this virus actually cause disease?

Caroline - The HPV can cause cancer by damaging the cells in the cervix and it's a persistent infection. And the damage to the cells can lead over many years to the changes that could become cervical cancer.

Chris - It's really common isn't it? And so only a fraction of people who actually encounter the virus go on to get the disease. Do we know why?

Caroline - Absolutely. And we don't know why some people will go on to develop cervical cancer and others won't. I think it's important to know that the human papilloma virus can also cause other cancers of the head and neck, the throat, and other genital cancers in both men and women.

Chris - And the vaccine will combat all of the above will it?

Caroline - The vaccine that's currently being used in the UK is incredibly effective. We've already seen a decrease in the number of warts that we're seeing in our clinics.

Chris - Yes because the virus also causes genital warts as the piece we’ve just heard there said

Caroline - Certainly in the women under 18, there's been a 92 per cent fall in warts over the last five years. So you know it's a staggering effect. Obviously it's going to be some years before we'll see the decrease in cervical cancer, because that takes longer to develop. But certainly the vaccine that's being used will prevent up to 90 per cent of cases of warts, and 70 percent of cervical cancer.

Chris - The way in which we go about cervical screening has changed in recent years though hasn't it, compared with previously, where we used to take a smear and look at cells under the microscope. Now people are taking a swab and they're looking for the DNA of the human papilloma virus. Why has that been that shift? And is this going to be as good, or better?

Caroline - And that's right. And you see now that we know so much more about the development of cervical cancer, and we know that it's so strongly linked to HPV, that instead of looking under the microscope at smears from all women, we are screening women by testing them for high risk HPV. Those that don't have high risk HPV don't need any further testing, and those who do will then have their slides looked at in the same way as we did in the past.

Chris - Does it have less of a failure rate? Because lots of people previously were having to come back because they got inadequate smears and so on, is it better in that respect?

Caroline - It's better from that point of view, and it means that less women are going to be having the unnecessary and very worrying investigations and treatments that they were having before. And we want to make sure that we're just picking up the women who've got the disease, rather than screening too many healthy women.

Katie - Now Graham cervical screening is obviously important for women but what is the risk for men when it comes to HPV.

Graham - So as Caroline alluded to, HPV can be linked to other cancers as well, such as head and neck cancer. In recent years seen it associated with some forms of oral cancer, anal cancer, penile cancer vaginal and vulval cancer, now they’re rarer forms of cancer but is associated with all these different sorts so it's an issue for men as well.

Katie - How do you test if a man's got HPV. You can’t obviously do a cervical screening.

Graham - Yeah, and this is the issue there's not screening programs for things like anal cancer in the UK, or indeed in many countries, because there’s not a good screening test.

Katie - So what do you do?

Graham - You look at vaccinating men, and that's something that has been introduced now. So from autumn this year boys aged 12 to 13 will be vaccinated as women have been as well. And that's a key kind of weapon in our arsenal in combating HPV in terms of causing cancer for this group.

Katie - Do we have an estimate of how impactful that will be? Because obviously it was just girls who were being vaccinated for a good few years before.

Graham - Yeah. In Australia they've been using this vaccine since 2013. You know, in terms of cancer, that's still very, very early, because cancer takes many, many years to develop due to HPV, but all the data from Australia shows that you're getting less high risk changes, less infection with the HPV types that can cause these cancers.

Katie - Do we know who's most at risk when it comes to HPV? Does it break down by any particular demographic? Is it certain age ranges?

Graham - I mean, I think the important thing to say is that, in terms of if you look at all HPV types you know, 90 percent of the population are going to be exposed to an HPV type, it is a really common virus. It’s more normal to have it than not have it but you know, obviously increased numbers of sexual partners, then you’re more at risk as you are of any sexually transmitted infection.

Katie - What would you see as being the main challenges for tackling HPV going forward then?

Graham - So I think one of the exciting things that's in development, they're looking at now a vaccine that's got nine HPV types in it, because as Caroline said you know, the current vaccine will protect against 70 percent of the HPV types that cause cervical cancer, but actually the nine valent vaccine will up that 90 percent, so I think that's the development.


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