Measles has hit the headlines after the recent outbreak at Disneyland California left 127 new cases in its wake. Unfortunately, this episode is indicative of a worrying trend amongst parents towards not vaccinating their children against such eminently preventable diseases.
Measles is far from a harmless illness, as the author of a heavily-panned book for sale on Amazon would have you believe (I shan’t do it the service of mentioning the title). It’s true, a lot of children who contract it will only be mildly affected, with the typical rash, fever, and flu-like symptoms. However, complications can range from severe, such as pneumonia and blindness, to life-threatening, such as immediate or delayed inflammation of the brain (encephalitis).
The disease is caused by a highly infectious virus – up to 90% of non-immune people will be infected by contact with an infected individual. It is spread by air-borne droplets (through sneezing/coughing, for example), which can remain active for up to two hours outside the body. In the early 1980s, measles was responsible for 2.6 million deaths annually, worldwide. By 2013, this figure had fallen to 145,700 – a substantial drop, but still over 400 potentially avoidable deaths every day. The development of an effective vaccine – the MMR (measles, mumps, and rubella) – and its mass rollout amongst the world’s healthcare systems was integral to this decline.
The difficulties faced by the MMR in the late 1990s are well documented – the publication by the Lancet of a paper claiming there was a link to autism was the crux of this. This paper has since overwhelmingly been shown to be flawed, erroneous, and plain reckless to be frank, but the damage was done; immunisation rates fell across the UK to a nadir of 80% uptake in 2003/04. To put this into context, because of how infectious measles is, the target uptake rate to effectively prevent transmission and protect individuals in a given population is around 95%. This is based on the concept of “herd immunity” – that is, once enough people in a community are immune, the disease cannot transmit amongst them. The Guardian has a great little graphic to illustrate vaccination rates and their effect on disease here.
Since that low point of a decade ago, uptake rates have risen in the UK, with MMR hitting 92.7% in 2013/14 – still short of a target, but a vast improvement. Despite this, however, there are still pockets of resistance to vaccination.
It’s very difficult to attribute this to a single cause – in reality, it seems to be due to a variety of reasons and opinions to one extent or another. Some parents worry about the safety of giving their children too many vaccines in a short space of time, others still worry about the vaccines themselves making their children unwell. However, I personally feel one of the overriding issues is complacency. Measles is hardly seen on a day-to-day basis by the general population in developed countries – quite aptly illustrated by the premature declaration by US Health Officials in 2000 that “measles has been eliminated”. Comments like this are, and have proven to be, dangerous through engendering complacency; the obvious question then becomes “if the disease is eliminated, why should we continue to vaccinate our children?”
The answer to that question is simple: the Disneyland outbreak, on a larger scale, would be the likely outcome. It is the very fact that so many have been vaccinated, that herd immunity is at such a significant level, that has prevented your children from contracting this disease. Vaccinating your individual child does so much more than just that – you protect not only them but other children and adults in your community by boosting the herd immunity. We’re all benefiting, and we keep an eminently preventable disease eminently preventable.
By Dr. Martin Saweirs – drmartingp.com