Ought we compel people to be vaccinated?

by David Copp and Gerald Dworkin

We have argued in a recent article in 3 Quarks Daily that there is a moral obligation for those who are able to safely be vaccinated against serious diseases such as measles and COVID-19 to do so. The gist of the argument is that, when certain factual conditions are met, people have a duty to accept vaccination. There are two conditions. First, there is a significant benefit to the person who is vaccinated and little risk. Second, there is a significant benefit to those to whom the person might otherwise transmit the disease. The benefit is a reduction in the risk of serious harm, which obtains if the disease is life-threatening or seriously threatening of significant pain, physical or emotional damage, or significant expense or effort to avoid these, to a significant subset of the population. We will refer again to these conditions, so let’s have a term for them. Call them the “factual preconditions” of an obligation to accept vaccination.

In this essay we are interested in a different set of issues–those surrounding the use of legal coercion to enforce the moral duty above. It is important to see that the two questions are distinct. There are moral obligations that we do not use the law to enforce. For example, we are generally obligated to tell the truth.  People often lie when they are obligated not to do so.  But lying is not generally a criminal offense.  Suppose that someone who is seriously hurt and trying to get to an emergency room in his car, asks us where the nearest emergency room is.  If we gave him false directions, we would clearly be failing to comply with a moral obligation to tell the truth in such circumstances. But, to our knowledge  there is no law which requires us to tell the truth in such a circumstance.

This, of course, only shows there is no existing legal enforcement of all truth telling–except in many particular cases, e.g. court testimony, taking out a bank loan, etc. Perhaps, as they say, there oughta be a law that requires truth telling. But a little thought shows that there are many good reasons not to have such a law. Such a law would be  generally unenforceable. For another thing, such a law would be overly broad, since people are sometimes entitled to speak falsely. Further, people have a right to privacy that would be infringed by an overly broad law requiring truth telling. Most important, we have a right to free speech and a law requiring us to speak truly would infringe this right.   

So the existence of a moral obligation to do something is not in general sufficient to justify having a law that requires it. There are cases where violating a moral obligation would harm no-one.  I ought to apologize when I do something wrong, but by not apologizing I normally do not harm anyone.  No-one thinks there should be a law that requires apologizing. There are cases where there is a moral obligation to do something but we have a right not to do it. In such cases, as with the speech example, it arguably would be illegitimate to create a law that requires these things even if they are obligatory.

Moreover, the existence of a moral obligation to do something is not in general necessary to justify having a law that requires it.  Consider traffic laws.  There is a moral obligation not to drive recklessly or carelessly.  But prior to legislation, there was no moral obligation to drive on the right or left side of a highway, or to drive at this or that speed. Yet it is legitimate to have laws that require us to drive on the right or the left as well as laws that set speed limits.  Such laws are for the public good. People can object that such laws interfere with our freedom, and they do, but they are justified by the harm they prevent. 

Our argument that there is a moral obligation to get vaccinated was based in the harms that not vaccinating causes or risks causing to others.  Our argument that it would be legitimate to have a law that requires vaccination will also draw on these harms and risks of harm.  For, in general we think, it is legitimate to have laws requiring people not to cause harm, or risk of harm, to others. Here, what we mean by “harming someone”, is to wrongfully set back an interest of theirs that they have a right to have protected.  According to this definition, for example, you do not harm me if you beat me in a fair competition, or if you give me a failing grade on an exam, because even though you set back an interest of mine, I have no right to be protected against losing or against failing the exam.  But you do harm me if you punch me in the nose, or put a drug in my drink, because by doing these things you set back an interest of mine and you do this despite my having a right to be protected in this interest.    

Perhaps there are cases where it would not be legitimate to have a law requiring or prohibiting some harm, even with this definition of harm.  These would be cases where there is a right to have an interest protected, but not to have it protected by law.  We will discuss some apparent examples.  But we will argue that the state can legitimately protect us against the harms and risks created by those who do not accept vaccination — at least in case of a public health crisis, and perhaps more generally — provided that our factual preconditions are satisfied. 

Notice that even if it would be legitimate to have a law requiring people to get vaccinated, it does not follow that it would be good public policy to have such a law.  And even if it would be a good thing to have such a law, many questions remain about the details, such as questions about how stringent the requirement should be, and about whether it would apply in general or only in public health emergencies.  We do not think the law should require  people to be forcibly vaccinated.  We will argue instead for a law requiring vaccination that penalizes refusal with a fine.  So we need to deal with three issues.  Call them the legitimacy issue, the public policy issue, and the issue of details.

In the U.S. context, people will often wonder whether a proposed law would be constitutional.  We shall set aside this issue and instead focus on background philosophical issues .

There have been laws that require vaccination. Massachusetts enacted a smallpox vaccination requirement in 1809.  It was designed to protect public health and safety, and it was held constitutional in Jacobson v Massachusetts.  As a condition of school enrollment, state governments require children to be vaccinated against an array of vaccine preventable diseases, including diphtheria, measles, rubella, and polio. To be sure, many states allow exemptions for medical reasons, or for reasons of belief, including religious beliefs. Some states allow vaccination to be required In a public health emergency.  In such an emergency, individuals who refuse to be vaccinated for health reasons or reasons of belief might be required to quarantine themselves.  Americans generally accept that military conscription is a legitimate use of state power, and the military requires troops to be vaccinated against a range of vaccine preventable diseases.

Our current freedom from the scourge of a variety of diseases that used to kill and harm many people is due to widespread and often mandated vaccination or other public health measures.  Smallpox was eradicated in the 1970s due to widespread vaccination.  Polio has almost been eradicated due to widespread vaccination.  The impact of measles has been greatly reduced due to widespread vaccination. In each case, vaccination requirements have played a role, either requirements imposed on school children as a condition of enrollment or, as in the case of the fight against smallpox in Massachusetts, wider requirements. Those who refuse vaccination against these diseases, and others, are free-loading on the submission of countless others to public health requirements to be vaccinated.

There are also requirements that are analogous to requiring vaccination. Many states have imposed legal requirements to wear face masks when in public, justified by public health concerns during the COVID-19 pandemic. Many if not most jurisdictions require drivers to wear seatbelts and motorcyclists to wear helmets at least partly out of public health concerns.  

It is true that vaccination involves a physical intrusion into the body, and there are very few legal requirements to submit to such intrusions as opposed to penalties if one does not.  But there are clearly laws which allow physical intrusion. Police can, provided they obtain a search warrant,  conduct body cavity searches to search for evidence of a crime such as drug possession. They can conduct body cavity searches at a border or airport without a search warrant. Drivers can be required to submit to a breath test or a blood test if they are suspected of driving while intoxicated.  Perhaps the closest analogy to requirements to be vaccinated are the laws that allow forced medication of a psychotic patient to render  him competent to be tried for his crime.

Of course, one could argue that all such requirements are illegitimate, so the existence of these laws can only show that a law requiring actual vaccination would not be unprecedented.  

Without taking a stand on laws permitting forced vaccination we will be dealing exclusively with laws which require vaccination under penalty of fine or imprisonment. 

Our argument rests on the harms and risks of harm created by not getting vaccinated, or by not having one’s children vaccinated.  In general, we think, a state is justified to prohibit behavior that seriously harms, or creates significant risk of serious harm to others — where, again, by “harming someone” we mean to wrongfully set back an interest of theirs that they have a right to have protected.  

Are there exceptions, cases in which a state would not be permitted to prohibit behavior even though it would seriously harm others or create a serious risk of harm to others?  Can we be required to donate blood if we have a blood type that is in short supply?  Not donating does not harm anyone, it only fails to help them.  So the harm principle does not clearly apply.  Requiring the donation is not requiring us not to harm others.  Can we legitimately be prohibited from driving since in driving we set back the interests of other people who use the roads by creating a risk of injury, property damage, or death?  We don’t think that it is wrong to create such a risk simply by driving, so we don’t think we harm other people simply by driving.  But we think we would harm other people by driving in a reckless manner or by driving while intoxicated.  And we are legitimately required by law not to drive in these ways.  We are required to do what we can to reduce the risk of harming others when we drive.  We think it would similarly be legitimate to require people by law to reduce the risk of infecting others by getting vaccinated. 

What specifically are the harms and risks of non-vaccination.  We think there are five.  First, non-vaccinators create a risk that they will transmit the disease to others if they get it.  Second they actually do harm these others if they get the disease and transmit it.  Third, they are weakening the community’s protective herd immunity, or reducing the chance that the community will achieve herd immunity, even if only to a small degree, which increases the risk to everyone that the disease will spread in the population.  (Herd immunity exists when enough people in a population have achieved immunity to the disease, either through vaccination or infection, to make its spread unlikely.)  Fourth, if herd immunity has been established in the community due to the behavior of others, who have gone to the trouble of getting vaccinated, the non-vaccinators are free-loading. Finally, fifth, if the non-vaccinators have children and refuse to vaccinate them, then they are creating a risk to their children. For if the factual preconditions we mentioned at the outset are true, we are dealing with a disease that is significantly worse than any risk from the vaccine.

In a public health emergency involving a disease like COVID-19, the harms and risks of harm are greater.  For herd immunity has not been achieved and the disease is actively spreading in the community.  Once there is a vaccine, herd immunity can be achieved, but only if enough people get vaccinated. Not getting vaccinated reduces the chance that the community will achieve herd immunity, which increases the risk to everyone that the disease will continue to spread in the population.  Also non-vaccinators are at serious risk of getting the disease and, if they do, there is the risk that they will transmit it to others. 

These harms and risks can be somewhat mitigated if non-vaccinators quarantine themselves, so a requirement to accept vaccination could provide the alternative of quarantine.  It might require a person either to accept vaccination or to be quarantined. 

All in all, then, we think that the harm principle would justify the state in requiring people to accept vaccination provided that the factual preconditions we mentioned earlier are met.  Note that a person who cannot safely be vaccinated for some reason must be exempted from the requirement. This is because one of the key preconditions is that the vaccine promises to bring a significant benefit to the person who is vaccinated and little risk.

So much for the legitimacy issue.  We now turn to the public policy issue.  Granted that it would be legitimate, we still must face the question whether it would be good public policy to require vaccination.  The fundamental standard to use, in thinking about this, we think, is a kind of efficiency standard.  Would a given proposed policy regarding vaccination be reasonably expected to lead the society in question to achieve, or would it significantly help the society to achieve, or to sustain, herd immunity? 

This issue is intertwined with the question of detail, since it might be good public policy to fine people who fail to accept vaccination even if it would not be good public policy to permit public health officials to forcibly vaccinate people.  To simplify, we will only consider a policy of fining people who fail to accept vaccination, either for themselves or their minor children.  Such a policy might treat a refusal to accept vaccination as a misdemeanor.  It would amount to a failure to show reasonable consideration for the health of other people.

There is the issue of cost.  We assume that if there is a good reason to have a law requiring vaccination, the cost of the vaccination should be borne by the state or included in insurance.  A model for how to do this is the flu vaccine.

Clearly, as we have already said, a well-designed vaccination requirement would exempt people who cannot safely be vaccinated for some medical reason.  Should a well-designed law also exempt people who have religious or philosophical objections to vaccines?  We think not.  People should not be permitted to harm or to create risk of harm to others, not even if they have religious or philosophical objections to avoiding creating the harm or the risk.  But since some people have objections of these kinds, the law arguably should permit them instead to make a different kind of contribution to public health, much as conscientious objectors to military service are permitted instead to make a different kind of contribution to the public good.

The issue whether such a policy would be a good one to implement depends on social and political circumstances in the jurisdiction in question.  A policy that would be effective in one social environment might be highly ineffective in another one.  This is for at least five reasons.  The core reason is the problem of non-compliance.  There is the ideology of freedom.  There are the problems of misinformation and misunderstanding, either about this vaccine or vaccines in general.  There is the problem of lack of trust.  And there is the problem of enforcement.

Some citizens will not comply with a requirement to be vaccinated.  Others will resist strenuously and perhaps even violently.  If enough people in a certain jurisdiction will not comply, or will resist, especially if they will resist violently, a vaccination requirement will not likely be successful in getting us to herd immunity.  Given the recent experience with requirements to wear face masks in the United States, It is clear that there will be non-compliance and resistance in the U.S. to a requirement to allow oneself to be vaccinated.  Police officers who are expected to enforce such a requirement might themselves refuse to comply, and refuse to enforce the requirement, in the way that some refused to comply with face mask requirements.

We have already alluded to one reason why people might refuse to comply and might even resist a vaccination requirement.  They might view the requirement as an illegitimate interference with their liberty.  A philosophical reply likely wouldn’t be an effective way to combat this idea since it likely is held for ideological reasons rather than on the basis of argument.  Appeals to a concern for the public good, or to a duty to contribute to the public good might help.   

Another reason to expect there would be widespread non-compliance, and even resistance, to a vaccination requirement is the widespread misinformation or at least misunderstanding about vaccines. We refer to the anti-vax movement and its promotion of misinformation about vaccines. There are also conspiracy theories about vaccines.  To be effective, a vaccination requirement would need to be accompanied or preceded by an information campaign that explained how vaccines work and how it can be known that they are safe and effective.  This campaign would have to target a generalized fear of vaccines as well as worries about particular vaccines.

Lack of trust in government and in particular public health agencies, such as the Centers for Disease Control and the World Health Organization, is yet another obstacle to the effectiveness of a vaccination requirement.  Can this particular vaccine be trusted to be safe and effective? Even if people are not worried about vaccines in general, they might worry about a particular vaccine that has been developed and approved in a rush, under political pressure.

Finally, there is the problem of enforcement. We have already mentioned the point that police officers who are expected to enforce the requirement might refuse to do so.  They might themselves be moved by the ideology of freedom, by misinformation, or by lack of trust. The problem is deeper than this, we think, since public policy leaders themselves sometimes fail to support public health requirements and might resist enforcing a vaccination requirement.  They might also be intimidated by those who would violently resist a vaccination requirement.

Unfortunately all of these obstacles to the effectiveness of a vaccination requirement, and strategies for combating them, would have to be weighed carefully.  The paramount goal must be to achieve and sustain herd immunity against vaccine preventable diseases, at least when our factual preconditions are met.  There can be no fixed rule about how to do this.  These issues are especially pressing now, during a public health emergency, when a dangerous disease is spreading in an uncontrolled way through a vulnerable population.  To control the disease we need a vaccine, and we need enough people to accept vaccination.  If appeals to health concerns and to public spiritedness are not enough, and if information campaigns are not sufficient to overcome resistance to a vaccine, a vaccination requirement is one tool to consider.  Yet it is not an easy tool to use with success.

Fortunately, there might be another way forward.  According to research by the Associated Press-NORC Center for Public Affairs, in late May, only about half of Americans said they would get a COVID-19 vaccine if one were available, but only one in five said they would refuse.  Another 31% simply weren’t sure if they’d get vaccinated.  Acceptance by about 70% of the population might be sufficient to achieve herd immunity, so if this data from late May remains accurate, a nudge might be enough to get the population over the line.  What kind of nudge?  It might be sufficient to issue an order requiring vaccination even if no penalty is attached to a failure to follow the order.   


David Copp and Gerald Dworkin are both Distinguished Professors of Philosophy Emeritus at the University of California, Davis.



“Mandatory Vaccinations: Precedent and Current Laws,” Kathleen S. Swendiman, Legislative Attorney, March 10, 2011 Congressional Research Service 7-5700 www.crs.gov RS21414