Vaccination and Autism: A Continuing Controversy

 Vaccines are often heralded by medical professionals as one of, if not the most, important inventions in healthcare to date. A vaccine is “a preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease” [1]. The first vaccine (smallpox) was created in the 1790’s and the development of vaccines for other infectious diseases has since saved millions of lives worldwide[2]. Despite their obvious success in protecting the public from a range of serious communicable diseases, conflict has permeated the history of vaccines. Anti vaccination movements surged into action across the world following the enactment of mandatory vaccination laws, the first one being passed in Massachusetts during 1809[3]. In Britain, some people who were anti-vaccination protested because they felt inappropriately governed by the ruling class, and others were subscribers to the alternate forms of “medicine” more accurately described as quackery, that demonized vaccination[4]. No matter what decreases in morbidity and mortality have been seen as a result of vaccines, there have always been a cohort of individuals opposed to vaccination.

               The CDC website contains a vaccine schedule for children 0-6 yrs old that is recommended to parents and healthcare professionals. There exists no federal legislature mandating the vaccination of children, however, every state mandates certain vaccines for children wishing to enroll in school[5]. Avoidance of this “mandate” is made easy for parents who are anti-vaccination:  all US states do have the option of legal exemption from vaccination based on philosophical, religious or medical grounds [6]. Philosophical Exemptions are currently available in 18 states. One must object to all vaccinations and therefore, a person receiving such an exemption will be completely unprotected against the many diseases that the CDC recommends vaccination against. Forty-eight states currently offer some type of religious exemption, with the criteria varying from state to state. The basic argument for religious exemption is that a person feels mandatory vaccination contradicts their religious beliefs, and therefore impinges on the right to practice their religion. While some states allow personal religious beliefs/interpretation to be sufficient enough for exemption of vaccination, others require that the person in question belong to a religion that explicitly prohibits invasive medical procedures 6. All 50 states permit medical exemption upon the grounds that vaccination would be detrimental to the health of an individual (as confirmed by a medical doctor or a doctor of osteopathy) 6. An individual opposed to vaccination certainly has options for avoiding the matter. At the interface of such people  and scientists/medical professionals occurs an ongoing debate about the values and harms of such vaccines.

While one of the clear values of a vaccines is the decrease in prevalence of the disease being vaccinated against, the afore mentioned tremendous success of vaccines has ironically contributed to the increasing numbers of parents that choose not to vaccinate. Thanks to the measles, mumps and rubella (MMR) vaccine, millions of lives are saved. Many parents who decide against vaccination have never witnessed something like the measles kill a child. Inexperience in this regard renders parents inappropriately dismissive of something that’s “just the measles”[7]. (Calandrillo, (Abstract Only)). Caused by a virus in the paramyxovirus family, Measles is a “just” the highly infectious disease that is responsible for the largest amount of child deaths worldwide. Despite the availability of this vaccine, 164, 000 deaths resulted from measles globally in 2008[8]. An infected individual will run a fever and have other typical flu-like symptoms, a rash and small white spots in the mouth on the cheeks. Most worrying are the complications that can occur with the measles. Encephalitis (swelling of the brain caused by infection), blindness, pneumonia and diarrhea can all occur as a result of contracting the virus 8. Despite the nonchalant attitude people of this generation have towards diseases like the measles, it is a serious disease, with a very real possibility for causing lasting harm to an individual. An interesting resource for the general public is a section of the CDC website entitled; “what would happen if we stopped immunization?” It states that between 1935 and 1963, deaths due to measles were averaged to be 450 annually[9]. To give a clear idea of the effect loosing herd immunity could have, the CDC estimates that if we stopped vaccinating altogether, we could expect measles deaths to rise to about 2.7 million per year worldwide9. While this is an extreme example of loss of immunization, the point is still the same; as immunization rates dwindle, the rate of measles will increase.

However, can one really blame concerned parents for doubting the current value of a vaccine that protects against a disease that has not been seen in the USA for multiple decades, and using an exemption as a result of this doubt? On the one hand, we live in a world where international travel is now commonplace and therefore the exposure a person experiences is not limited to their immediate surroundings. Travelling to other regions of the world where immunization is not the standard poses a health risk for unvaccinated people. Not only does it affect the person actually doing the travelling, but it has the potential to adversely affect the community they return to in the United States, especially if it is a community with low immunization rates. An article in the New England Journal of Medicine[10] documented such an occurrence in a community in Indiana during 2005: A 17 year old unvaccinated girl brought Measles back from a trip to Romania, and attended a church gathering of about 500 people. Around 35 members declined vaccinations, sighting reasons such as fear of adverse side effects (e.g. autism) and 31 of these people (89%) contracted Measles [11]. This was the largest outbreak of Measles in the US for approximately a decade and although no deaths occurred, the public health response necessary to control the situation was an expensive one. Despite the risk of infection from overseas travel/exposure to someone who has the disease, a parent might argue that the risks associated with actually getting the vaccination are greater than the risk that someone in their child’s daycare will bring a scarcely seen disease into school one day.

The obvious risks of vaccinations include redness, tenderness, itching, bruising and lump formation at the site of injection[12]. These relatively superficial and short lasting side effects seem to me to be an acceptable trade-off for the immunity acquired through vaccination. More of a nuisance than anything, these side effects are not the ones that concern parents so much as to stop them from vaccinating their children. A list of the “very rare” side effects associated with the various vaccines recommended for children offers an interesting light in which to view vaccines. All vaccines hold the potential to cause severe allergic reaction and some vaccines are associated with other serious adverse effects. For example, the MMR vaccine is associated with deafness, long-term seizures, coma, lowered consciousness and permanent brain damage[13]. The CDC says: “…this happens so rarely, experts cannot be sure whether they are caused by the vaccine or not”[14]. These are the types of side effects anti-vaccination parents are worried about. Officials have admitted that they don’t know whether instances of these symptoms in children are actually caused by a vaccination received prior to the onset of the symptoms.  

One adverse effect that is splashed throughout the media is the notion that vaccines are causing autism. . A publication in worldwide medical journal, The Lancet, February of 1998, sparked the beginning of this issue. Is there a link between vaccination with the Measels, Mumps and Rubella (MMR) vaccine, and autism? Doctor Andrew Wakefield, a British gastroenterologist, suggested just that after performing a study on 12 autistic children.  The assertion he made raised public outcry that seems only to be emphasized by the technologically accessible world we live in today.  Ten years later, anti-vaccination lobbyists litter the internet with campaigns to raise awareness about the danger of the MMR vaccine. In February of 2010, the lancet issued a retraction of Dr. Wakefield’s article, saying that it was scientifically flawed. The fear had already been raised though, and today, despite the retraction, parents of autistic children claim that it was a vaccine, or a combination of them, that caused their child to develop the developmental disorder.

An important fact that is often skimmed over is that MMR is administered within the first few years of life; coincidentally the same time during which many children are first diagnosed with autism . Doctors like Paul Offit (Children’s Hospital of Philadelphia) who are pro-vaccine, attempt to reassure parents further by presenting the numerous studies done to evaluate the potential link between vaccination and autism.  One such study in the New England Journal of Medicine, entitled “A Population-Based Study of Measles, Mumps and Rubella Vaccination and Autism” involved a retrospective study on Danish Children born between 1991 and 1998. It examined the incidence of autism spectrum disorders in the unvaccinated group of children during these 7 years, and compared it to the incidence of vaccinated children. The study concluded that evidence indicated a lack of association between the MMR vaccine and autism [15]. Similarly, an article in the Official Journal of the American Academy of Pediatrics summarizes the conclusions agreed upon at a conference that was held to review data available on the issue. Among the data reviewed was pathogenesis epidemiology and genetics of Autism Spectrum Disorder in addition to data available about the supposed link. They concluded that the evidence suggests no link between Autism and the MMR vaccine[16]. The scientific community seems to conclude absolutely from these studies that there is no link between vaccination and autism. It seems to me that while these data are clear and precise epidemiological studies, they cannot speak for any particular individual. That is; it is not possible to prove through the kind of research that has been done that in any one individual, a case of autism wasn’t caused by a previous vaccination. The frustration that emanates from scientists with regard to parents who are reluctant/refusing to vaccinate is obvious.  If scientists could transmit the necessary information in a more constructive and less berating way, perhaps the gap between pro and anti vaccinationists could be narrowed.  

Perhaps people who scrutinize parents for not vaccinating their children need to take a harder look at the information available, and not automatically dismiss the potential risks associated with immunization.  This becomes more and more relevant the farther out we get from incidences of a disease in this country. At what point does the risk associated with vaccinating become more real, in comparison to the risk of contracting a scarcely observed disease? Exemptions are a route utilized by parents who believe the risk of getting vaccinated to be higher than the risk of contracting the disease. If the risk of vaccinating seems to be comparatively larger than a few decades ago (which seems to me to be true), why is vaccination still so widespread, and still recommended by healthcare officials?

In the section of the CDC website devoted to vaccines and immunizations, the analogy of a leaky boat is used to explain why we continue to vaccinate for certain diseases whose prevalence has decreased over the years:

“It's much like bailing out a boat with a slow leak. When we started bailing, the boat was filled with water. But we have been bailing fast and hard, and now it is almost dry. We could say, "Good. The boat is dry now, so we can throw away the bucket and relax." But the leak hasn't stopped. Before long we'd notice a little water seeping in, and soon it might be back up to the same level as when we started.”[17]

Using this metaphor; the last thing we want/need is for the water level to creep back up. Given the potential for a disease to re-emerge in this country following poor adherence to the recommended vaccination schedule, it is important to think about the consequences of having what is essentially an “opt-out” system via exemptions.

As previously suggested, perhaps the scientific community needs to be less final in their presentation of the relevant data and devise more tests to further explore the link between autism and vaccines. The gap could also be lessened by ensuring parents are truly well educated on the matter. Yes, getting vaccinated does pose a risk, however minor. This fact should not be dismissed as negligible by the scientific community as it seems to be in some cases. The fact parents should not gloss over is that choosing not to vaccinate poses a risk also. One of the problems with allowing exemptions is that it allows for people to opt-out of vaccinations easily, without providing much reason in most states. It is possible to envision that certain individuals will protest vaccination just because of autism stories splashed on the news. While a fear of autism may be legitimate in their eyes because of the stories they’ve heard, or because of personal experience with another of their children, it is concerning that people may dismiss vaccines automatically, without giving though to the consequences it may have for their own child’s safety, and for the community at large as well. If the number of people choosing not to vaccinate rises in the context of misinformation or incomplete information, both these people, and the scientific community are to blame.

               Collaboration between both sides of this debate could truly benefit all parties. Most importantly, if the scientific community could adjust the communication of their data so that it is more accessible, and so that the general public could actually understand the information in a specific context, more informed decisions could be made. More informed decisions could also be made if anti-vaccine individuals are able to understand fully the risks posed to their child by choosing not to vaccinate, as well as understand the scientific data (even retrospective/epidemiological studies). It seems that both parties present their arguments in separate venues to their respective supporting crowds. A consortium of sorts may allow for more progressive and fruitful discussion. The challenge will be for pro-vaccine individuals and anti-vaccine individuals to find a common ground that will allow the general population to remain safe, without compromising the health/safety of individuals.