Monday, 22 April 2013

The Welsh measles epidemic - How did this happen?

The measles epidemic is centred on Swansea and Neath Port
Talbot but has began to spread into adjoining areas. How the hell,
in the age of mass vaccination, was this allowed to happen?
(Pic : BBC)

The latest figures point to there being just over 800 cases of measles in Wales - most of which in Swansea and Neath Port Talbot areas - but starting to spread into Bridgend (~30 cases), as well as the Hywel Dda and Powys local health boards.

As the schools recently returned from Easter holidays, it's likely that the epidemic won't peak for another two to three weeks, and Health Minister Mark Drakeford (Lab, Cardiff West) has said so himself. It's on course to be one of the worst measles epidemics in the UK & Ireland for some time. It's also unclear whether this epidemic may have claimed its first fatality too.

I think it's worth giving the main LHB involved – Abertawe Bro Morgannwg - a rare pat on the back with regard the public health response. I think they've handled this well and reacted quickly to the situation, including setting up the emergency vaccination programme.

I think it's nonsense to suggest that they, or the Welsh Government, were "slow to respond".
Due to the nature and background to this, there's not much else they could be doing.

Demanding oral statements in the Senedd - telling AMs what they presumably already know - is, to me, an pointless gesture for the time being.

A brief background to the MMR scare

Scares about vaccines aren't new. Did two/three particularly
damaging scares relating to MMR in the 1990s lead
to this epidemic?
(Pic :
Vaccines generally work by using weakened strains of diseases to enable the body's immune system to recognise them as "dangerous", and build up a natural immune response to those diseases ready for when they're encountered in the future.

Vaccines will have side effects as a result of that immune response – usually a mild form of the disease being vaccinated against, in rare cases something more serious.

A combined measles, mumps and rubella (MMR) vaccine was first introduced to the UK in the late 1980s. A strain of mumps used in the manufacturing of the MMR vaccine used at the time was linked to an 1 in 3000 chance of developing a form of meningitis as a side effect. This strain was replaced, but there was a fall in uptake of the MMR as confidence was shaken. This resulted in measles outbreaks in the early 1990s, so the UK government launched a more aggressive vaccination drive in response.

In 1998, gastroenterologist Andrew Wakefield – already a leading critic of MMR, and who had originally linked it with inflammatory bowel diseases - published a research paper in The Lancet. He suggested a connection between MMR, childhood digestive problems and a severe form of autism, which he eventually termed autistic enterocolitis.

Andrew Wakefield published more results from the same study over subsequent months and years, and suggested via a press conference (an unusual step in scientific circles) that it would be "safer" to suspend combined MMR and use three separate vaccinations instead. That attracted wider media coverage, leading to a major public health crisis at the turn of the century.

This wasn't
helped - circa 2001 - by Cherie Blair refusing to say whether Leo Blair had been vaccinated with MMR or not. She was absolutely within her rights not to do so to be honest, and that smells of the press trying to whip up an unnecessary storm by trying to expose "hypocrisy". Hundreds of articles were written based on the Lancet paper over several years, and public confidence in the MMR vaccine fell across the UK.

The South Wales Evening Post, based in Swansea, led its own separate campaign called "MMR parents' Fight for Facts" in 1997. There was a reported 14% drop in MMR uptake in the Swansea area, though it's worth pointing out that the Evening Post never actually told parents to avoid vaccinating their children.

Then, as the years went by, it became clear that there was no evidence backing Andrew Wakefield's claims. The original pathological evidence was manipulated – a mortal sin in scientific research. The research had also received financial backing from lawyers specifically looking to sue vaccine manufacturers. There were also other "conflict of interest" allegations which he failed to declare to The Lancet; including looking to launch a testing kit for "autistic enterocolitis" and patents for a new measles vaccine.

It wasn't until 2010 that The Lancet formally retracted the paper. Andrew Wakefield was eventually found guilty of professional misconduct and was struck off the medical register by the General Medical Council. The link between autism and MMR has been discredited, and it's unlikely that autistic entercolitis even exists as a disease.

What might have caused this measles outbreak?

Herd immunity is a concept where if a certain percentage of the population is immunised against a disease, the risk of someone who isn't immune catching that disease is reduced. They would be less likely to come into contact with someone who isn't immune, and it would be harder for people to carry that disease (act as a vector).

Vaccines are never 100% effective. So herd immunity is vital, even to protect those who have been immunised, those with supressed immune systems through medical treatment, or those for whom the effect of a vaccine has worn off.

Every child not vaccinated against measles  for whatever reason - especially if it caused vaccination rates to fall below the threshold for herd immunity - would've put the rest of the population at risk.

For measles, the percentage for herd immunity to kick in is around 90%, though the Welsh Government and public health officials aim for a 95% immunisation rate to be on the safe side. That means if 90%+ of children in the Swansea area were immunised against measles, there shouldn't have been a mass outbreak.

In November 2012, just under 42,000 children in Wales alone weren't vaccinated against measles, and a significant number have only been partially vaccinated - probably because they haven't received booster jabs. If they haven't been vaccinated against measles, they may well have not been vaccinated against many other childhood diseases either – including mumps and rubella.

Look at the graph below to see how MMR vaccination rates (the yellow line) changed between 1997-2003 (the start of the Evening Post campaign and the peak of the Wakefield scare) and how long they took to recover to the 90% level:
Childhood immunisation rates in Wales since 1997.
(Pic : Public Health Wales, Click to enlarge)

Looking at the age breakdown of the current recorded cases of measles, the bulk of those affected appear to be between the ages of 4 and 20 - roughly corresponding with the period of 1992-2010 - with most of those being between the ages of 4-14 (1998-2010). Public Health Wales have pointed to particular concerns about a "lost generation" of under-vaccinated children aged between 10-18.

Age breakdown of current recorded measles cases as of April 17th
(Pic : Public Health Wales, Click to enlarge)
As to why vaccination rates fell, you've got to point to vaccination conspiracy theories like those surrounding MMR. They were based off bad science, pushed by media headlines and not properly cleared up by public health authorities.

This would've happened on the Welsh Government's watch – they're responsible for public health - as the panic surrounding MMR "peaked" between 1998-2002.

I'm pleased to say that there's no sign that the safety of MMR has ever been brought into question in the Senedd. AMs have always been more concerned about falls in immunisation rates, so they get a thumbs up from me. That's wasn't enough though, obviously, and I can't tell if there were any press statements from individual AMs to the contrary.

Looking through the Assembly's records, the then Health Minister Jane Hutt (Lab, Vale of Glamorgan), was aware of the problems and was "taking action" with health authorities at the time. Similarly her successors, including Edwina Hart (Lab, Gower).

As you can tell from the public health statistics, those measures took their time to work. Though there was a spike in vaccine uptake around 2001, the Blair ruckus and ensuing further uncertainty might have partly contributed to the fall afterwards.

t looks as though trust in MMR in Wales wasn't properly restored until at least 2009-2010.
That's a big window in terms of age groups affected by this - many will be adults now - and immunisation rates remain below the desired 95%. All of that will have impacted herd immunity for a considerable period of time.

There are separate vaccines for measles, mumps and rubella available that aren't linked to MMR, but they have their own set of concerns and there's nothing wrong with MMR in the first place.

Another possible conclusion is that parents who were concerned about MMR, didn't have their children vaccinated with these separate vaccines either. That could've been through lack of availability, or because they became suspicious about all measles vaccinations as a result of the scare stories.

In fairness, I doubt any parent is sceptical about MMR now, as the queues to receive vaccines in the Abertawe Bro Morgannwg area show.

Science and health in the media

As much as sex sells, scaring people sells too.

There's a reason health stories are given pride of place in sensationalist sections of the press. Issues surrounding our personal or children's health are a primal fear. We're not confronted with death and disease as often as we were 50-100 years ago, so anything that shatters our cosy, clean reality is pounced upon, and more often than not, blown out of proportion.

Scare stories about vaccines have been going on for decades. There was one about the whooping cough vaccine in the UK during the 1970s and 80s that resulted in falls in immunisations, and two major outbreaks that killed 100 children.

I don't think it's a question of seeking to "blame" anyone, as that would be counterproductive. These things are going to happen – even if this could've been easily avoided - but it's understandably distressing for any families caught up in it. We need to first and foremost make sure, once this epidemic if over, that it never happens again.

Firstly, there are problems in the reporting of science in the media. Some journalists are specially trained to report science, but that doesn't mean they have a scientific background. It's unlikely local newspapers will have any science journalists on their staff. An exception here would be in-depth investigative journalism, which helped expose the MMR scare fraud in the first place.

For example, everything on this blog is commentary. I try my best to go through any evidence and come up with what I consider "educated guesses" - including this.

Most health or science stories in the media are nothing better than an "educated guess". It's usually reduced to the bare bones for sake of explanation, or cherry-picked for the best headlines, with no consideration given to the science behind those stories, which – admittedly – is usually quite dull or unnecessarily technical. There's also a problem with transparancy when it comes to pharmaceutical development and science in general, which creates so many doubts in people's minds that it gives conspiracy theorists enough material to work off.

Sometimes ordinary people will get caught up in and dragged along by convincing conspiracy arguments in the media, especially if they come from someone in a position of authority – like a doctor, established medical journal, perhaps even including journalists, celebrities and politicians.
People are perhaps also more cynical about government advice on areas like this because of their handling of things like BSE.

The British press – especially the tabloids - went for the MMR scare with gusto. People in Swansea will be just as likely, if not more so, to read The Mirror, Daily Mail, Express or The Sun as the Evening Post. That's before mentioning TV coverage and the impact of the internet in particular - where any idiot can say anything, myself included.

So, the Evening Post shouldn't be singled out in this, as it's probably overstating the influence of the local press. However, people might "trust" local papers more than Fleet Street, and any campaign the local press support might be seen to be more creditable. Although the defence of the Evening Post's coverage in the 90s seems a little strident, at least they're now calling on parents to vaccinate their children with MMR.

It's fine to report the news, it's another thing entirely to get involved in "campaigns" built on shaky foundations. In this case, those shaky foundations are as much The Lancet's fault as anyone else's. Andrew Wakefield merely loaded a gun the press were waving around irresponsibly. And they threatened the health of a generation of children by placing doubts into parents' minds about the safety of MMR.

When you read the specifics of the original 1998 Lancet report and the fallout, including :
  • The small sample size (12 patients)
  • The fact MMR had been used for up to a decade - even withdrawn - in other countries like Japan before being introduced to the UK with no affect on autism rates
  • Improvements in the identification of autism that would've resulted in more autism diagnoses
  • MMR is administered around the same time the symptoms of severe autism develop anyway
  • Nobody has been able to reproduce the results (a fundamental requirement in scientific research)
....I'm amazed they didn't laugh it straight into the bin.

The difference between a legitimate suspicion or scientific hypothesis and a conspiracy theory is that a conspiracy theorist is convinced they're right, and tries to fit evidence around their conclusion. They neglect anything to the contrary, perhaps coming up with related conspiracy theories to explain those away.

The mindset of conspiracy theorists means it's impossible to convince them that their theories are wrong. They usually just move the goalposts in a search for meaning with regard linked coincidences, expecting the worst from people, companies, politicians or institutions. If too many people get carried away by things like that, it can do serious harm.

The link between measles and children being hospitalised, disabled or dying is proven. There's statistically a much greater chance of a child being injured in a car journey on the way to being vaccinated, than from the vaccine itself.
Also, a health service is supposed to maintain the population's health and well being through thoroughly tested and proven treatments. It's an emergency service. It's not supposed to act like a supermarket, giving people "choice". That includes offering de rigueur separate vaccines over MMR and things like homoeopathy.
Ultimately though, it's a parent's responsibility to get their children vaccinated. It's not their fault they were misled – as Glyn Beddau pointed out a few weeks ago– but I find it hard to believe that anyone with a proper understanding of how vaccinations work, or herd immunity, would've avoided vaccinating their children.

If anyone wondered why science is still a key part of the school curriculum alongside maths and literacy, it's for reasons like this.

A healthy level of scepticism is a good thing for society, especially if that results in more of us being able to put decision-makers on the spot when they try to sneak things past us. But that's worthless if it's built on a foundation of bullshit, as it has been with MMR scares and vaccine conspiracies in general. Come to think of it, these two clowns can probably demonstrate it better than I ever can :



Post a Comment