Land of the free and home of the anti-vaxxers – one in four American adults believes in a link between the MMR vaccine, autism and a cover-up by the CDC. Is this due to a lack of information or general distrust?
Infectious diseases have always posed a great threat to modern society. They can become a huge burden for the healthcare system and are a special threat to vulnerable groups. In urban, densely populated areas, viruses and other pathogens can spread rapidly and cause major outbreaks, as seen recently during the COVID-19 pandemic or currently with the rapid spread of bird flu cases in the United States (DocCheck covered that here). Luckily, there is a tool to mitigate the impact of many pathogen-caused diseases – vaccines.
Since the invention of vaccines in 1796 (Edward Jenners smallpox vaccine), numerous diseases caused by pathogens can be held under check, and the severity of symptoms in case of an infection can be reduced. The smallpox vaccine laid the foundation for developing modern, safe vaccines that generally have only minor side effects – including those given to young children as part of their basic immunization.
One of the most important vaccines, highly recommended by governments and medical committees, is the MMR vaccine (measles, mumps and rubella vaccine). It is highly effective against infections caused by measle, mumps, or rubella viruses. Each of these pathogens can cause serious diseases with a high likelihood of complications in young, unvaccinated children. According to the Centers for Disease Control and Prevention (CDC), the vaccine is classified as very safe and has only a few side effects. Yet rumors and conspiracy theories have been spreading for decades, claiming there is a correlation between the MMR vaccine and the increase in autism diagnoses in the past. The CDC denies the correlation between the two and backs its statement with current and prevailing research, relating the increase in autism rates to a higher awareness of the spectrum disorder, better diagnostic methods and a widening of the spectrum.
Even though the MMR vaccine is an inherent part of immunization schemes worldwide, nifty Americans have cracked the code once again. A recent survey conducted among over 1,500 U.S. adults by the Annenberg Public Policy Center (APPC) from the University of Pennsylvania, revealed one in four adults to believe the CDC is lying when ensuring the safety of the MMR vaccine and denying a link between autism and the vaccine. But is that part of a conspiracy theory, or do they simply not know any better?
When asked about their knowledge of the measles virus itself, it becomes clear that U.S. adults are insufficiently informed. Only 59 % of the survey participants knew that the virus can be spread via coughing or touching contaminated surfaces. Regarding the infectious potential, only 12 % of the participants estimated correctly, that people can be infectious already four days before developing a measle rash. 55 % answered they were unsure for which time people could spread the virus. This shows how important it is to educate not only children but adults on how to avoid the spreading of these diseases.
According to the survey, not only knowledge on the spread of the virus is lacking – even more worrisome is the fact, that the majority of adults does not seem to know how dangerous an infection with measles can be when unvaccinated. Vulnerable groups such as pregnant women can suffer dire consequences from infection with measles, amongst others giving birth to low-weight babies or premature births. Only 38 % of the survey participants were aware of this.
The easiest way to avoid an infection or a severe course of the disease remains the MMR vaccine. Receiving only one dose is already 97 % effective against rubella. When receiving both, the vaccine is 97 % effective against measles and 88 % effective against mumps.
Especially considering recent measles outbreaks in the U.S., the CDC keeps encouraging parents to vaccinate their children. They ensure that the MMR vaccine is safe and that there is no link between autism in children and the vaccine. Of the surveyed adults, 24 % do not believe that the statement of the CDC is very accurate, and an additional 3 % are unsure about this statement. 12 % of the participants not only question the CDC’s credibility but are thoroughly convinced that MMR or similar vaccines do cause autism in children. But if no recent study points towards that potential link, where does the misconception stem from?
The assumption that there is a link between vaccines and autism in children leads back to a paper by Andrew Wakefield et al. from 1998. Their research, conducted on 12 children, was published in The Lancet and allegedly found a correlation between autism and the MMR vaccine. The paper has since been retracted due to fraudulent data handling and a conflict of interest. A link between autism and vaccines has never been proven since, which does not stem from a lack of research. Cochrane studies, meta-analyses, and systematic reviews, including data from several million children did not reveal any correlations. However, the harm has already been done, as the media coverage of the issue following the publication of Wakefield’s article was enormous. Newspapers and TV shows worldwide reported on the alleged link between the vaccine and autism. Even the retraction and mentioned studies disproving Wakefield’s findings could not eradicate the belief from some Americans and has instilled a certain vaccination hesitancy in people’s minds – the misconception prevails.
It therefore comes as no surprise that the number of measle cases was seen to increase again in the past years. The vast majority of cases occurred in non-vaccinated individuals. This shows how big and long-lasting the influence of the media can be on the decision-making of individuals. Especially during the COVID-19 pandemic misinformation and fake news about the coronavirus could be found everywhere, which instilled people with hesitancy and skepticism towards science and research. Hence, one would also expect the same skepticism to spread towards the CDC.
However, as revealed by the AAPC, the COVID-19 pandemic does not appear to have increased the portion of adults who are skeptical towards statements of the CDC. When compared to surveys conducted in 2018, the relative proportions remain the same – around a quarter of participants mistrust the CDC.
While one in four is still too many, it almost comes as a relief that facts and scientific consensus remain the most important influences on health-related decisions for the majority of American adults.
Image Source: CDC, Unsplash
