In January 2017, the world's first anti-cancer vaccine, Gardasil, became available free of charge for everyone in NZ aged 26 or under - including non-residents under the age of 18. The vaccine, which protects from Human Papillomavirus (HPV), was previously only available for free in NZ to women under 20, so the decision to include men was an exciting one - and very significant from a public health perspective. As one of the most studied and safest vaccines available, it has already resulted in the near elimination of genital warts in age groups that have been vaccinated.

Unfortunately, the backlash from a small minority threatened to dampen the effectiveness this fantastic development could have.

Just as 2014 New Zealander of the Year Dr Lance O’Sullivan has recently found himself publicly targeted for the commonsense advice of vaccinating children and speaking out against the “misinformation based on lies” of the anti-immunisation camp, there has been a lot of heated debate (including on our own Facebook posts) between those trying to attack the HPV vaccine and those who understand its proven effectiveness against a virus that can cause genital warts and cancers of the anus, penis, tongue and throat.

We completely stand by our promotion of the HPV vaccine – it’s a vital part of the community’s defence against a virus that, without immunisation, is likely to affect 80% of the population. So we thought we’d get an expert scientific view on the subject.

Dr Helen Petousis-Harris is a senior lecturer in the Department of General Practice and Primary Health Care at the University of Auckland and Director of Research at the Immunisation Advisory Centre. Like Dr O’Sullivan, she’s come under fire in the past from anti-vaxxers, but as the latest member of the World Health Organisation’s Global Advisory Committee on Vaccine Safety (she’s off to the her first meeting of a three-year appointment at the start of June), we’d rather take her considered and educated view on Gardasil over some of the baseless scare stories spread via social media.

So, Helen - where did this backlash to Gardasil come from?

It came from an unexpected quarter – normally when there’s opposition, it tends to come from the far left but this time it came from the ultra-conservative far right and it was around the fact that HPV was a sexually transmitted disease and this was of particular concern to people who feel that sex should be after marriage and therefore you’re promoting promiscuity.

Then – and these are my observations – there a number of people involved in the legal system in the US where they have something called the Vaccine Injury Compensation Program where there’s very large amounts of money set up for claims against the industry. And it’s ‘no fault’, so the litigant doesn’t have to prove the vaccine has caused some kind of injury, just that it might be possible.

So once this idea of promiscuity started, you began to see ideas that the vaccine might not have been tested properly or the vaccine might cause these adverse effects and it grew and grew and grew.

But what about all these claims that it is a “toxic killer cocktail” and has caused deaths?

I guess the core of the claims about deaths and any other serious events is what’s known as the “post hoc” fallacy where if a precedes b, there’s a presumption that a causes b. And this myth is a big mountain to climb. Deaths are monitored across any study and post the introduction of the vaccine, and now that hundreds of millions of doses of the vaccine have been produced there’s a large amount of data globally on deaths and serious events and there’s simply no difference between those who have been vaccinated and those who haven’t. Even when you have details of individual cases, there’s no evidence that the vaccine could possibly have played a role. It’s just very convenient for these people to say 20 people in the study died and then omit the rest of the details of what they died of.

One of the biggest claims of those against Gardasil is that it causes Complex Regional Pain Syndrome…

I think that back in the original trials, Complex Regional Pain Syndrome hadn’t been raised as a particular issue, that came later. But in clinical trials, participants are followed up very closely for new health events, so, for example, by the time the trials for the new Gardasil-9 were underway, they looked particularly for it. It was administered to 15,000 individuals, all of which were followed up for 70 months for new medical conditions and, out of these 15,000, two individuals developed Complex Regional Pain Syndrome and both related to a previous injury. One of the other adverse events is supposed to be Postural Orthostatic Tachycardia Syndrome (POTS) which was developed again by two of the 15,000 individuals, one of which was more than three years after immunisation. So it’s fair to say that out of 15,000 cases and other big studies that use large linked databases, there’s no evidence that these events have occurred.

So, you’d probably say the same about the link to Chronic Fatigue as well?

If you are trying to say immunisation is risky, it’s really good to find something vague that’s hard to diagnose, that might have a multitude of standards for diagnosis, and that might also be a spectrum. It’s also very convenient when a lot of your population are adolescents and at an age when all sorts of health issues can present themselves.

It was anticipated before the vaccine was developed that you would have to look for auto-immune type conditions and some studies were done to check the base line of auto-immune conditions in certain age groups just to see what you’d expect to see by chance. So we saw it coming – although I’m not sure anyone saw it coming quite to this extent, because the anti-vaccination lobby grabbed hold of these conditions.

What they’ve also got is a group of pseudo-scientists who are no experts on vaccines or sexual diseases and they propose scientific-sounding theories as to how vaccines cause these conditions and then invent their own syndromes and publish articles in what some of us call the vanity press - where you pay some money and they’ll publish anything you want.

All of this is feeding into those groups who want to show that these vaccines actually cause something and then you’ve got scientific data that continues to show that it’s highly unlikely that the vaccines cause these things.

Added to the myths about negative effects, plenty of campaigners still claim a vaccine against a sexually transmitted disease like HPV shouldn’t be used because it promotes promiscuity.

That’s not true either. It’s been a claim for a while and it’s not the case – in fact it’s quite the opposite. A 2016 research paper titled “Tempest in a teapot: A systematic review of HPV vaccination and risk compensation research” looked through 20 studies involving more than 520,000 individuals and revealed “consistent, replicated evidence… refuting that there is an associated between HPV vaccination and risky sexual behaviour”.

The report went on to say that “In fact, some studies found vaccinated women showed lower risky behaviors than unvaccinated women, indicating a tendency toward less risky health behaviors. These findings should alleviate parental and provider concerns that HPV vaccination will lead to risky sexual behaviors.”

How about the fact that campaigners point to a growing movement against Gardasil?

I think now the penetration is enormous but the information is recycled and repackaged and pushed out constantly into Facebook feeds. So you’ve got the same amount of people active as you’ve always had, but now they’re reaching further and they’ve become very brave because they can hide behind the internet and say things that most people wouldn’t say.

For example, in the 90s with the stories linking the MMR vaccine to autism in the UK you had a plummeting of coverage followed by outbreaks in the UK where the news was more prevalent. But if you look at New Zealand at the same time, nothing happened – there’s no evidence it had an impact on coverage. I think that’s because we had nowhere near the penetration of social media and nowhere near as many sites that disseminate this stuff. Now the penetration is more, but I don’t believe it’s any more people being active.

Some anti-vaccination campaigners say the crisis around birth defects linked to Thalidomide in the 50s and 60s proves that long-term negative effects of drugs can’t always be pre-empted and Gardasil could pose a threat at some stage in the future.

I always love that argument because it is used all the time as an example but the fact is the US Food and Drug Administration prohibited the use of Thalidomide because it was not satisfied with its safety profile. So the Thalidomide disaster never happened in the US because the system worked and prevented it being used. Today that lesson has prompted higher levels of pharmacovigilance and turned it into a global effort. So for vaccines, every single country in the world has to have a vaccine safety monitoring system of some sort and then the data from the 126 countries is pooled at a World Health Organisation centre in Upsala in Sweden. This system has proven to work very well for vaccines – so far they have picked up every single vaccine safety issue that has come up for years. So, yes, there have been issues but they’ve all been detected.

And how do you feel about those who have said that because some schools have opted out of New Zealand’s Gardasil programme, it shows it’s not safe?

The case I know of in Timaru involved, to the best of my knowledge, a member of the board of trustees going along and saying ‘I’ve seen the light and it’s dangerous’ and this board, in its infinite wisdom, prohibited the programme taking place. My question is what qualifies a board of trustees to make health decisions that go against the recommendations of the Wold Health Organisation, pretty much every county’s health authorities, and pretty much every other health and scientific community?

How have you felt after being singled out for attacks on your professional ability because of your role in helping promote vaccination?

It’s quite hard the first time someone attacks you and maybe a little upsetting, but once you’ve been attacked many, many times you grow a harder shell and stop worrying about it. It seems to be something about these people that when they turn and attack they can be quite vicious – but it’s one thing attacking me because I’ve criticised them and that’s okay, but this goes further in the US where they make death threats and – what’s really awful – when they target parents who have lost a child to vaccine preventable disease and have told their story only to be attacked by these people. I think that’s about as low as you can go. They clearly have no scruples with their tactics, which I think says something about them.

For The Ministry of Health’s guidelines and information around Gardasil, visit the Medsafe website.