Vaccine Hesitancy: A Global Threat
Vaccinations are one of the most important and controversial health discoveries of the last millenium. There is increasing, questionable “evidence” that vaccinations are harmful; however this is vastly outweighed by the evidence that vaccinations are fundamental in the maintenance of public health. Indeed, increasing reluctance by parents to vaccinate their infants and children was described by the World Health Organisation as one of the top ten threats to global health. This week at Skeptific, we’re explaining the history of vaccination controversy and debunking some myths around vaccinations.
How It All Started…
In 1998, Wakefield et al published a paper which supposedly showed a link between bowel disease, autism and the Measles-Mumps-Rubella (MMR) vaccine. This study was published in a highly-revered medical journal, The Lancet, and quickly picked up traction, causing a media wildfire. The paper was, however, fatally flawed. Firstly, the paper described an onset of “behavioural symptoms” in 9 of the 12 children studied. The parents of these children had described an association between the onset of these issues and the timing of the MMR vaccine. It is difficult to draw any conclusions from findings in 12 cases, based on anecdotal evidence, given the hundreds of thousands of children who had been immunised against MMR. This was inevitably misreported and caused major unrest amongst parents. Ultimately, it was discovered that Wakefield supported a competing vaccine, and he therefore aimed to discredit the MMR vaccine. He had presented false results; and was accused by the General Medical Council of being “dishonest”, in one of the most damaging medical hoaxes of the century. His license to practice medicine was revoked and the paper was retracted by The Lancet. Subsequent studies and reviews of these studies, including a reputable Cochrane systematic review of all published evidence in this area, have definitively concluded there is no association between the MMR vaccine and autism. Unfortunately, the damage was done.
Following this scandal, uptake rates of the MMR vaccination have dropped considerably in the UK and globally. This not only presents a danger to the children who are not inoculated against MMR, but it more importantly creates a wider public health issue. If a sufficient percentage of a community is immunised against a disease, it will also prevent transmission of that disease to individuals who cannot have vaccines (e.g. due to a weakened immune system). A disease, like measles, can effectively be eradicated from a community if 95% of children receive the vaccinations. If this drops to fewer than 90%, these diseases can quickly spread again. After 1998, the MMR vaccination rate in the UK dropped to 80%. Although it has been increasing steadily since, as public confidence in the MMR vaccine has grown; since 2016 it has been on a decline again, with a vaccination rate of 90.3% in 2018-19.
So, What’s the Problem Now?
There is a concern that vaccines are associated with long term health problems and allergies. There is also increasing reluctance from the vegan community, to use vaccinations, which are tested on animals and may contain animal products. We’re feeling a little skeptical about some of these claims…
Vaccines have additional materials within them, to improve the effectiveness of the vaccine and increase the body’s immune response against the disease. One such adjuvant is aluminium, which has been shown to be harmful in large doses. There is therefore a concern that the aluminium in vaccines is also harmful. Reviews of all the trials done so far, comparing vaccines with and without aluminium adjuvants, have shown that there are no short-term or long-term safety concerns associated with aluminium. Whilst aluminium adjuvants may cause temporary pain and redness at the injection site, it is not associated with adverse events, e.g. seizures. This makes perfect sense, as aluminium is present in tiny doses in vaccines. It is also present in tiny doses in things we encounter everyday, like drinking water and food packaging.
Some scientists have found a correlation between immunisations and allergy rates. Whilst immediate allergic reactions to vaccinations could occur, these are rare and there is little evidence to suggest vaccines are implicated in long term allergic sensitisation. Interestingly, the reunification of East and West Germany is the largest unintentional cohort study of allergy incidence. In East Germany, the vaccination rate was 100% and the allergy rate was virtually zero. Following the reunification of East and West Germany, two notable changes occurred. Firstly, immunisation rates dropped in East Germany (as parents were no longer under government order to vaccinate their children), and secondly, East Germany began adopting a more Western lifestyle (including improved sanitation). Allergy rates began to rise. This has been used as an example to substantiate two hypotheses. The first is that immunisations are not, in fact, associated with higher allergy rates. The second is the “hygiene hypothesis”, that exposure to particular microorganisms protects against allergic diseases, by contributing to the development of the immune system. Lack of exposure due to increasing hygiene, therefore worsens immune tolerance. More recently, a cohort study, in which 466 children were followed from birth to 5 years, showed there was no association between early childhood vaccination and subsequent allergic sensitisation.
This is a moral, rather than a scientific concern. It is therefore difficult to argue on the basis of scientific evidence, and beyond the scope of this blog. However, given that infants cannot make decisions for themselves, decisions should be made to prioritise the child’s welfare. Parents opposed to vaccination tend to maximise the negative aspects of vaccination whilst minimising the effects of infectious diseases. This raises questions of whether it is in the best interests of a child, who has not made a choice to adopt a vegan lifestyle, not to be protected against potentially fatal diseases. With an outbreak of measles in the USA in 2019, and increasing litigation rates for “negligence”, there is already hypothetical discussion of adults suing their parents for not vaccinating them in their childhood.
A Final Note
Even the most reputable sources of information may misrepresent conclusions. Ultimately, there is no conclusive evidence to show that vaccinations are harmful. There is however significant epidemiological evidence of the harm caused by the diseases, against which vaccines aim to confer protection. Many of these diseases are no longer in our living memory, but if vaccine hesitancy continues to grow, they are likely to return.