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Oxford Uehiro Prize in Practical Ethics: May the state limit the free speech of individuals who advocate against vaccines intended to combat infectious disease? by Miles Unterreiner

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This essay, by Oxford graduate student Miles Unterreiner, is one of the two finalists in the graduate category of the inaugural Oxford Uehiro Prize in Practical Ethics. Miles will be presenting this paper, along with three other finalists, at the 12th March final.

May the state limit the free speech of individuals who advocate against vaccines intended to combat infectious disease?

Freedom is the most contagious virus known to man.

-Hubert H. Humphrey


Philosophical arguments concerning freedom of speech have traditionally focused upon which types of expression the state apparatus may justly limit, and under which circumstances it may do so. The state has therefore been the locus of history’s most celebrated works on the subject, including John Milton’s Areopagitica (1644), chapter 20 of Spinoza’s Tractatus Theologico-Politicus (1670), and perhaps most famously J.S. Mill’s On Liberty (1859). Mill’s argument in favor of the free exchange of ideas remains today the most lasting and the most relevant, and his formulation of the “harm principle” – that “the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others” – continues to undergird significant components of law and policy in industrialized democracies today.[1]

The modern state about which Mill wrote, however, now faces a peculiarly modern challenge that it is increasingly finding itself ill-equipped to handle: an admixture of infectious disease with a series of public campaigns intended to undermine the very vaccination programs designed to combat infectious disease.

Information spreads quickly now. So do viruses. What is the state to do when the two intertwine?

This December, an outbreak of measles erupted at Disneyland theme park in Anaheim, California, United States of America. By mid-January, the virus had spread north to San Francisco, infecting (thus far) at least 70 people across the state.[2]

Measles is a highly contagious airborne disease that typically manifests itself in a red splotchy rash that covers the entire body and is often accompanied by a fever and cough. In certain cases, however, measles is much more dangerous. Persons with weakened immune systems – such as those afflicted with HIV or AIDS – are much more susceptible to the disease, and the measles mortality rate is significantly higher in developing nations. According to the World Health Organization, approximately 145,700 persons died from measles worldwide in 2013.[3]

According to public health officials, the best way to stop the spread of measles is to receive a vaccine shot – an inert sample of the virus that effectively trains the body’s immune system to resist the real thing. Prior to the start of the United States’ national measles vaccination program in 1963, that country reported between 3 and 4 million cases of measles annually. Of persons infected each year, between 400 and 500 died and approximately 48,000 were hospitalized. Thanks to intensive national vaccination efforts, however, the measles virus has been considered eradicated in the United States since the year 2000.[4]

So why is measles back?

The answer can largely be traced not to a new or mutant form of the virus, but to the spread of something much more difficult to combat: false information.

Antivaccination campaigns now pose a significant threat to public health efforts around the globe. Such campaigns are sometimes grounded in objections based on religious, philosophical or ethical grounds. Frequently, however, they are based upon the distribution of incorrect empirical information about vaccines themselves.

In 1998, research in The Lancet, a British medical journal, appeared to demonstrate a link between the MMR vaccine – the vaccine most frequently given to children to prevent measles – and increased autism rates in children. The editor-in-chief of the British Medical Journal (BMJ) announced in 2011 that this research had been found to be fraudulent,[5] and the paper’s lead author was found guilty of professional misconduct and barred from practicing medicine in the United Kingdom.

By then, however, it was too late. MMR vaccination rates dropped significantly in the United Kingdom after the fraudulent Lancet article was published, from 91 percent in 1998 to 80 percent in 2003. The number of new measles cases rose accordingly, from 56 in 1998 to 1,370 in 2008.[6] By 2008, the disease was endemic to the UK, a country in which it had once been eradicated.[7] Professor Dennis K. Flaherty of the University of West Virginia has called the vaccine-autism scare perhaps “the most damaging medical hoax of the last 100 years.”[8]

“Despite the overwhelming evidence of the safety and effectiveness of the MMR vaccine,” continues Professor Flaherty, “the vaccine-autism connection gained traction on the Internet and was perpetuated by print and television media eager for increased circulation or higher ratings. Entertainment shows contributed to the controversy by offering vaccine-autism connection proponents a platform to make their case, largely unchallenged. By 2009, 1 of 5 parents in the US believed that vaccines cause autism in otherwise healthy children. Moreover, 10% of parents in a study published in 2010 were refusing 1 or more newer vaccines for their children.”[9]

What may the state do about all this, if anything? Certainly few people doubt that the state may permissibly spread correct information as widely as possible, or fund public health vaccination programs to encourage wider uptake of vaccines. But what if these strategies prove to be insufficient? May the state justifiably limit the free speech of anti-vaccination campaigners, and if so, on what grounds might it do so?

Anti-vaccination advocates have already begun to stake out a principled free-speech argument in favor of their cause. When every venue in Australia at which she had hoped to speak canceled her invitations this month, anti-vaccine campaigner Sherri Tenpenny’s organization replied that this tactic amounted to “bullying by vested interests who do not believe in informed consent, free speech and respect for other’s rights, and who appear to support censorship of thought and science.”[10]

Persons conditioned to believe in the inherent value of free speech – myself included – are often inclined to agree with Tenpenny that limiting speech in this way is not permissible. I believe the public has in mind here some form of Mill’s harm principle – that actions which do not harm others should not be limited by the state – combined with some sort of belief that speech acts do not cause “harm” in a morally relevant way.

But there are clearly at least some cases in which speech acts can be considered to cause harm, and in which the speaker may be rightly held responsible for the harm thus caused. Consider the case of John, who thinks that vaccines don’t work and has decided to host a public reading of a popular anti-vaccine pamphlet. In order to reach the maximum number of people, John purchases a loudspeaker and advertises the reading widely online. But imagine that John, his loudspeaker, and the assembled crowd all gather in a remote mountain village where the sound waves generated by loud noises are known to trigger deadly avalanches. John boldly asserts that his right to free speech outweighs the harm to others that is likely to follow, and begins to read the anti-vaccine pamphlet aloud into his megaphone. The avalanche that follows kills five people and injures 500. I think it is clear that John has harmed these people, and harmed them in the same sense that he would have harmed them had he stood on top of the mountain and drilled away at the snow with a sledgehammer.

Moral responsibility for harm caused by speech can clearly extend even to cases where the thoughts and beliefs of other persons intermediate between speech and the harm it causes. Imagine that John knows that there are two bridges across a narrow canyon, and that one of the bridges is faulty and likely to collapse. Nonetheless, when a band of unknowing travelers arrives at the canyon, John advises them to avoid the safe bridge because its construction was sponsored by a major pharmaceutical company. In the resulting collapse of the unsafe bridge, 3 people die and 47 are injured.

Speech is far from unlimited in the real world, where the law often delineates circumstances in which the state may limit free expression when it causes sufficiently proximate harm. Virtually every democracy, for instance, prohibits false advertising, in which companies make knowingly false claims in order to sell a product – one cannot make a claim that a product is safe if it has been conclusively shown to be dangerous, for example. After a long series of legal battles, cigarette companies are now required in many countries to mark their products and advertisements with labels informing consumers of the health risks – a clear limitation on unfettered free speech. Likewise, accurate nutrition labels are almost always required on food containers so that consumers know which ingredients are in the food they are eating; companies cannot advertise a donut, for example, as containing valuable vitamins when the donut in fact consists purely of butter, sugar, and chocolate flavoring.


Is waging an anti-vaccination campaign sufficiently like causing avalanches, or like advertising cigarettes, to warrant legal limitation? There are several arguments one could make to contend that it is not, and that anti-vaccination campaigns ought to qualify for free speech protection.

The first is that by leaving themselves unvaccinated, persons are harming only themselves, and that the self-harm caused by refusing to vaccinate oneself is itself something Mill would (and we should) protect under the harm principle. This is not so. Many persons harmed by anti-vaccination campaigns are children deliberately left unvaccinated by their parents, and Mill himself admits that one may harm another “not only by his actions but by his inaction, and in either case he is justly accountable to them for the injury.”[11] Persons who leave themselves or their children unvaccinated also pose a significant threat to the health of other parents’ children below the age at which vaccinations may be administered (usually 12 months of age); highly contagious infectious diseases, particularly airborne ones, are very easily transmissible to babies who have not yet been vaccinated.

The second objection will be that the harm caused is too indirect to warrant state interference – that there are too many steps in between advising people to avoid vaccines and children falling sick to justify limiting the original advice. But the number of steps involved does not necessarily indicate that a chain of causation is not clear. If I pull a lever which I know will give painful electric shocks to fifty people, is it any morally different if the lever will knock over a ball which will roll into a set of dominoes which will knock over their own chains of additional dominoes and eventually trigger a switch that causes fifty people to suffer electric shocks?

A third objection may be on practical grounds – that the state cannot possibly halt such speech in an age dominated by social media. Whether it would be right to stop the spread of false information and whether it is possible or effective, however, are two different things. The fact that the state cannot stop all theft, for instance, should not prevent it from prosecuting some thieves.


Limiting speech on public safety grounds need not take the form of men in black masks kicking down doors in the night to take away those with whom we disagree. It may be, depending on the nature and proximity of the harm caused, as innocuous as mandating a warning label to keep consumers fully informed of risks. (This is tricky in the vaccine case, since it is difficult to place a warning label on nothing, and nothing is precisely what antivaccine campaigners urge their fellow citizens to inject.) The precise form speech restrictions take, however, may vary; it is the basic ethical question of whether the state may impose some form of limitation that must first be answered.

I do not pretend to have answered it. This question deserves far more normative and empirical analysis than I am capable of giving it here. But whether anti-vaccination campaigns qualify for free speech protection is a question that may quite literally determine whether some people live or die, and it is at the very least a question worthy of further consideration.

[1] Mill, John Stuart. On Liberty. London: Longman, Roberts, & Co., 1869.

[2] Alicia Chang, “Measles Outbreak Casts Spotlight on Anti-Vaccine Movement,” The San Francisco Chronicle, 23 January 2015. Accessed 23 January 2015 at <>.

[3] World Health Organization, “Measles: Fact Sheet No. 286,” November 2014. Accessed 22 January 2015 at <>.

[4] Centers for Disease Control and Prevention, “Frequently Asked Questions About Measles in the U.S.,” 21 January 2015. Accessed 22 January 2015 at <>.

[5] Godlee, Fiona, Jane Smith and Harvey Marcovitch, “Wakefield’s article linking MMR vaccine and autism was fraudulent,” BMJ 2011; 342:c7452. Accessed 22 January 2015 at <>.

[6] Flaherty, Dennis K., “The Vaccine-Autism Connection: A Public Health Crisis Caused by Unethical Medical Practices and Fraudulent Science.” Annals of Pharmacotherapy October 2011 Vol. 45 No. 10. Accessed 22 January 2015 at <>.

[7] Batty, David, “Record Number of Measles Cases Sparks Fear of Epidemic,” The Guardian, 9 January 2009.

[8] Flaherty, Dennis K., “The Vaccine-Autism Connection: A Public Health Crisis Caused by Unethical Medical Practices and Fraudulent Science.” Annals of Pharmacotherapy October 2011 Vol. 45 No. 10. Accessed 22 January 2015 at <>.

[9] Ibid.

[10] Medew, Julia, “Anti-Vaccination Campaigner Sherri Tenpenny’s Tour in Jeopardy,” The Sydney Morning Herald, 20 January 2015.

[11] Mill, John Stuart. On Liberty. London: Longman, Roberts, & Co., 1869.

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2 Comment on this post

  1. It seems curiously authoritarian–or at least seems suggestive of a vein of authoritarianism rather richer than one might ordinarily hope for in an Oxford philosopher–to propose that the expression of opinions that might potentially be harmful be suppressed, rather than debated, further studied, exposed, denounced, or mocked.
    If, despite such treatment, such opinions continue to find purchase among a significant minority of people, it is surely for us to muse on our failure to convince, than to reach for a programme of political oppression. The dubious philosophical habit of reaching for the bizarre thought experiment rather than empirical data might be one such reason for an anti-vaccine parent not changing their mind.
    Meanwhile, and particularly in such times, no reasonable person will neglect to have their children vaccinated.

  2. The MMR-autism link has been found to be fraudulent, as noted in the article itself, fraudulent claims are generally not considered, morally or legally valid, under freedom of expression protection.
    So maybe the problem with regards to the MMR/autism example, is more a matter of how those people advocating NOT using vaccines should be held liable for the harm caused to people who mistakenly accept the fraudulent link, and consequently are harmed by measles.
    The moral dilemma is not what claims should be suppressed, but who should be held liable for the fraud?

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