By Sinéad O’Ferrall (@SineadOFGH)
We have so many effective vaccines against such a wide range of diseases, yet still so many people are dying from these diseases – mainly children, who are the most vulnerable. In 2011 alone, 1.5 million children died from vaccine-preventable diseases. Why don’t people use the available vaccines? Like all things in life there is no one simple answer. However, I will address one reason here – the Anti-Vaccine Movement (AVM).
Unfortunately, vaccines have always been subject to myths and hearsay, which have continued to fuel rumour mills, resulting in a lot of misinformation. As long as vaccines have existed, people have opposed them. In the 18th century, Edward Jenner created the first vaccine targeting smallpox as the historical smallpox epidemic was occurring. But even in the midst of an epidemic with no treatment and a high death rate, Jenner met resistance to his highly effective solution.
I believe the biggest myth prevalent today is the supposed link of autism to vaccination, particularly associated with the measles-mumps-rubella (MMR) vaccine. This myth arose when a paper written by Wakefield was published in the Lancet suggesting the link, however it was quickly disproved and the paper retracted in full. There were glowering inconsistencies in methodology and huge conflicts of interest. Unfortunately, the damage was done. The spark was out there and it quickly developed into wildfire. Wakefield’s study has never been able to be repeated and yet many other studies since have consistently found the opposite result – there is no connection between autism and the MMR vaccine.
Yet people continue to listen to pseudoscience, fear-mongering and straight up lies, perhaps because it is easier to understand, or perhaps because it is delivered in a cool and hip way on chat shows, hosted by attractive presenters and celebrities who have passion and who people aspire to be like.
We live in a society where fame seems to give people an infallibility that is usually reserved for the Pope. But when it comes to your health, the health of your child, and also that of your neighbour, can we afford to be so careless with the truth?
This is the truth:
According to the organisation Autism Speaks, “Autism spectrum disorder (ASD) and autism are both general terms for a group of complex disorders of brain development. These disorders are characterised, to varying degrees, by difficulties in social interaction, verbal and nonverbal communication and repetitive behaviors”.
While there is no one definite cause demonstrated yet, autism is currently believed to be heavily genetically influenced, with environmental factors also playing a role. These environmental factors include: premature birth, especially if before 26 weeks, increasing age of parents at the time of conception, gender – boys have a four times higher risk, and potentially viral or bacterial infections.
But let me be clear: whilst these are all theories that certainly may play a role, research is ongoing and we have much to learn. One final distinction is, that though these factors may increase the risk of developing autism, they do not cause autism.
The MMR vaccine contains three separate components that protect against three separate diseases: measles, mumps and rubella. These three diseases are all caused by different viruses that cause a variety of symptoms ranging from mild coughs, to the extremely serious condition encephalitis. Encephalitis is swelling in the brain due to inflammation and infection, it can lead to convulsions, brain damage, mental retardation and death (see Amendment 1). These three infections have no treatment post-infection, except for supportive care, so prevention is key.
These are well established diseases, and there is no doubt about their seriousness and severity. These are not diseases you want to catch or to let your child catch. Now, a lot of AVM followers will say that these diseases are no longer a cause of concern, since no one catches them anymore. But these viruses are still present in nature and without proper measures and continued efforts they will re-emerge.
This is where the vaccine comes in. The MMR vaccine is a live attenuated vaccine (LAV). LAV is a type of vaccine that contains a weakened but still live version of the infectious agent. Scientists manipulate the virus in the lab to replicate again and again until the point of exhaustion, and then use that virus to create the vaccine. This is the best way to stimulate the immune system to create an immune response to the three viruses, with minimal risk to the person. The virus still resembles the version encountered in nature, often referred to as the wild version, and therefore, is most effective at stimulating a strong and accurate response. When a person is exposed naturally post-vaccination, they are protected from the invader.
The AVM is fueled by the suggestion that rubella has a link to autism, leading people to conclude that the vaccine must also be. But let me put this plainly: study after study has been performed, and no link between autism and the vaccine has ever been established. However, a link to autism and rubella has been investigated with some small link proven. So if you want to protect your child from autism, they have much better odds if they are vaccinated. That is what the rigorously tested evidence says.
The other big argument that proponents of the AVM call upon, is another ingredient in the vaccine. The main component is the exhausted virus but other ingredients are added to preserve the vaccine and to boost the effect of the immune response. The ingredient that has received the most focus from the AVM is thiomersal. This is a mercury derived chemical that is added for its antifungal and antibacterial properties. But since controversy arose about the vaccine, despite overwhelming evidence to the contrary, it was removed from almost all vaccines as a precautionary measure. It is, however, still used in some flu vaccines. I have included {Amendment One} a small selection of studies looking at the link between thiomersal and autism and other neurological effects, but in summary there is no proven link to date.
Vaccines are often hailed as the single greatest public health tool. Just take the example of smallpox eradication, only made possible by vaccination. Multiple studies show that when vaccination rates goes up, disease rates go down. Vaccination saves the lives of both the individual and protects the community as a whole. If you question or doubt the safety or effectiveness of vaccines that is perfectly okay, it is a complicated field. Find reputable sources of information and critically look at the facts, not the rumours. I would suggest the Center for Disease Control (CDC), WHO’s factsheets, and The History of Vaccine websites as good starting points.
The next time you hear someone shouting out an anti-vaccine statement, that they are harmful or cause some condition or disease, check their qualifications. Check whether they have a Bachelors in immunology or pathology, or even chemistry before you take their word over qualified scientists and doctors, who have chosen their vocational paths because of a desire to help keep the general population healthy.
Recommended studies/ papers for further reading:
Studies reviewing and looking at potential links between thiomersal and autism:
http://www.cdc.gov/vaccinesafety/Concerns/Thimerosal/neuropsychological_Outcomes.html#q6
http://www.immunizationinfo.org/science/autism-and-thimerosal-danish-study
Eye on Global Health 