The debate about vaccination safety was recently pushed back into the spotlight after a measles outbreak in Berlin led to the death of an 18-month-old boy. Fifteen years ago, the United States had declared measles to be eliminated from the country. But as recent outbreaks can attest, the infection remains a problem, with over 20,000 cases reported in 2014, and 120 cases reported in January of this year alone.
More and more people have been brought into the debate. A recent article was published on the immunisation rates within Silicon Valley’s technology companies, based on data acquired from the California Department of Public Health. Interestingly, it was found that the immunization rates of Pixar and Google employees’ children were significantly below ‘herd immunity’ levels – the level at which the percentage of immunized people are high enough to stop any significant spread of disease. The organisations in question later reported that the data was inaccurate and out-of-date, releasing newer data with immunisation rates of over 85%.
Elsewhere in the United States, there is rising debate on whether vaccines should be made mandatory, with strong views being expressed on both sides. A recent CNN poll stated that nearly eight in ten Americans believe vaccination should be required for preventable diseases such as measles, mumps, and rubella. So with the majority in favour of vaccination, why do some people still doubt the safety of vaccines?
The cause of the first vaccine scare almost 20 years back is not the same as the reasons behind its current, persistent survival, and that is a crucial difference. Significant opposition to vaccines first began due to the combination of two independent events, coincidentally occurring at around the same time.
In 1997, scientists discovered that the growing number of vaccinations and booster jabs children were receiving was leading to a build-up of thimerosal within the body. Thimerosal is a vaccine preservative containing ethyl mercury. While few studies had been done on ethyl mercury, methyl mercury was a known toxin, so public health authorities played it safe and decided to eliminate thimerosal usage. The implication of danger however, caused a large reaction in the public, leading to a drop in vaccination rates, even after it had been reported that thimerosal poses no risk.
An infamous report was published by British scientist Andrew Wakefield around a year later, suggesting a link between autism spectrum disorder (ASD) and the MMR vaccine. Understandably, the public reacted strongly, however in the 17 years that have passed, the study has repeated at least 20 more times worldwide, none of which managed to find any link between ASD and MMR vaccines (or any other vaccine for that matter).
The report has since been retracted by the scientific journal in which it was published, for reasons including “insufficient data”. A large majority of Wakefield’s collaborators have requested their names be removed from the paper. It was also discovered that the study was funded by lawyers engaged in lawsuits against vaccine manufacturers. Finally, Wakefield was charged for ethical violations, including mistreatment of patients. One would find it hard to find a scientific statement more heavily disproven than this; and yet, the anti-vaccine movement persists, with the main objections being fears of harmful side effects and doubts of their necessity.
Images courtesy of: Breakthroughs/onequalitystandard