Issues in Interdisciplinarity 2020-21/Evidence in the anti-vaccine movement

Introduction
Many believe that the anti-vaccination movement emerged recently through the Internet. However, vaccine opposition arose as soon as vaccination started being popularised. Widespread vaccination started in the 1800s in England to prevent smallpox. It faced immediate opposition by the population: seen as ‘unchristian’ by some and as a violation of people’s personal liberty by others. The Vaccination Acts of 1853 and 1867 faced riots and saw the founding of the Anti-Vaccination League in London (1853) and the Anti-Compulsory Vaccination League (1867). Although the ways of expressing and spreading this opposition have changed since the 19th century, the motives behind it are still mainly the same, opposing public health and medicine to civil liberty and choice.

Biology
In biology, evidence seems to promote vaccination: the larger the vaccinated population, the better.

Yellow Fever
Yellow Fever is a disease prevalent in South America and Africa (90% of the cases) that can go from a mild illness to a fatal disease, including a rapid deterioration of kidneys, jaundice and bleeding diathesis. Additionally, yellow fever does not have any specific treatment; it is responsible for 200,000 cases and 30,000 deaths every year, with a Case Fatality Rate Case fatality rate for severe yellow fever of 50% or higher. As the disease is spread by mosquitoes, it cannot be eradicated, hence the importance of vaccination to reduce the victims of yellow fever. Research has shown that the yellow fever vaccine 17D (YF-17D) is efficient after 10 days in 95% of the patients and its protective effect may last for up to 30-35 years. Although the WHO World Health Organization recommends a single vaccination, study has shown that its efficiency is limited (with only 50.4% of Malian children and 27.8% of Ghanaian children still seropositive after 3-5 years), suggesting that another administration of the vaccine is required to reach an 80% immunity of the population, preventing yellow fever outbreaks.

‌Some evidence in the biological domain however also shows nefast effects of the vaccine. Several pathologies have been linked to this vaccination, such as transverse myelitis, encephalitis , meningoencephalitis and peripheral facial paralysis. Nevertheless, the vaccine remains the most efficient way to prevent yellow fever and its adverse effects are very low.

Vaccine efficacy
Vaccine efficacy is calculated according to the ratio of vaccinated versus unvaccinated people who catch a disease. According to the Centers for Disease Control and Prevention, ‌2 doses of IPV (polio) are 90% effective against polio and 3 doses are 99-100% effective (making the US polio-free since 1979), 2 doses of the vaccine against chickenpox are 90% effective (and reduce symptoms in case of the disease), and 1 dose of MMR vaccine is about 93% effective while 2 doses are 97% effective at preventing measles (leading to a 99% reduction in measles cases in the US).

Biological quantitative evidence therefore largely promotes (compulsory) vaccination, as the vaccines administered often have very high efficacy rates and help stop the spread or even eradicate specific diseases in certain countries. The few biological evidence used by the anti-vaccine movements often aims to show the causality between certain vaccines and diseases or infant deaths. However this evidence is often flawed or irrelevant statistically, compared to the number of lives saved by vaccination – preventing 2 to 3 million deaths every year according to the WHO - raising ethical questions on the 'collateral damage' of vaccination.

Ethics
When it comes to vaccination, Ethics take a step back from scientific evidence and look at human rights and the philosophy of actions. The ethical concerns at the origin of the movement are related to the nature and regulation of the vaccine. A tension emerges from this discipline: the worth of the individualas opposed to the community's.

Philosophy
Anti-vaccine movements question the importance of one’s freedom being overcome and how the latter is justified. This matter is discussed in terms of an individual's freedom to own their body, in addition to their freedom of belief and freedom of choice. Although vaccination is supported by Public Health for the individual's and, mostly, the greater good, can someone ethically be obliged to be vaccinated despite their refusal? As vaccines impact people's health, they should be allowed to make their own choice. The uncertainty of the object has engendered fear of harm among populations over time leading, in the most extreme cases, to trials like the American Henning Jacobson’s in 1905. His protest concerned compulsory smallpox vaccine based on an "ethical basis of autonomy and harm". Therefore, the movement bases its ideas on the worth of individual freedom compared to the common good. Is someone willing to accidentally die of a failed vaccination for the "greater good"?

Ethics in religion
Studies of anti-vaccination movements have revealed religious beliefs as the biggest argument of vaccine opposition. As a created element having animal origins, the vaccine has long been seen as « unnatural ». Thus vaccination was long considered « unchristian » or « evil » (therefore unethical), amplifying people’s unwillingness to be vaccinated.

New issues
Nowadays, additional ethical issues are raised. Technology and the Internet allowing the spread of people's concerns and opinions, especially through social media, are the perfect tool for the anti-vaccine movement to grow. Indeed, as people seek information on the subject, it has been observed that most of the sources encountered online have an anti-vaccine approach. However, most of these movements are founded on false assumptions or beliefs that feed the mistrust of governments and conspiracy theories.

Therefore, the ethical approach of vaccination is quite complex as it is quite subjective. On one hand, the utilitarianism approach promotes the enforcement of vaccines for the greater good of the population. On the other hand, the suppression of individual freedom, especially when it comes to products injected in one's body can be seen as very unethical. The anti-vaccine movements thus raise very interesting and essential ethical questions on freedom despite their often use of fake news as evidence for their cause.

Public Health
Public health as a discipline is the science of promoting the population’s health as a whole. It plays a crucial role in solving tensions in the evidence proposed in various disciplines, but also within them. Overall, public health professionals try to fight the anti-vaccine movement.

Compulsory vaccines
Governments can enforce mandatory vaccines, to promote herd immunity and avoid the resurgence of a disease. They base their evidence on principles commonly used in public health. The “harm principle”, developed by John Stuart Mill, is the idea that unvaccinated people could be a danger to society as spredears of the disease. Additionally, the “precautionary principle” states that when a country is threatened by a virus, the government must take preventive measures. These principles apply utilitarianism, prioritising the well-being of the majority rather than the individual's. Hence, evidence in biostatistics, showing that punctual negative effects are negligeable in front of the overall success of vaccines, mirrors public health’s goal of assuring the population’s safety (sometimes at the expense of the individual's).

However vaccine exemptions exist, based on the right of the individual's choice. The reasons can be medical, but also religious or philosophical. Nevertheless, these reasons's validity varies widely. In the United States, 43 states allow religious exemptions, while only 15 allow philosophic exemptions. Overall, public health does not leave much space for personal choice – which is one of the arguments used by anti-vaccination movements –, and some countries like the US seek to consider ethics more and reduce the number of compulsory vaccines.

Education
Education also has an important role when it comes to public health. This is essential as 43% of websites on Google associated to the keywords “vaccination” or “immunisation” are lead by anti-vaccination movements. Many of these websites report fake news and conspiracy theories (blaming for instance some vaccines to cause autism), in addition to social media platforms acting as “echo chambers”. However, 70% of parents go to the internet to educate themselves on vaccination, leading to a confused population, who does not have access to valid evidence on the subject. To educate parents and children, trained healthcare providers play a key role, going over the concept of herd immunity, remind the dangers of certain diseases, and explain the process of vaccines' commercialisation. Online education campaigns have also proved to be efficient. In Australia, 66% of parents and 88% of pregnant women started raising awareness and checking up on their children’s vaccination after having seen such campaigns. These strategies reduce the conflict between disciplines, simply by educating people instead of depriving them from their free will.