Victims, Vectors and Villains? Are Those Who Opt Out of Vaccination Morally Responsible for the Deaths of Others?

Guest Post by Euzebiusz Jamrozik, Toby Handfield, Michael J Selgelid

Re: Victims, vectors and villains: are those who opt out of vaccination morally responsible for the deaths of others?

Who is responsible for the harms caused by an outbreak for vaccine preventable disease?

Are those who opt out of vaccination and transmit disease responsible for the resultant harms to others?

Suppose that health care systems make vaccines widely available and easily affordable–but some choose not to be vaccinated, resulting in an outbreak. If the outbreak only affected those who could have been safely and effectively vaccinated, but nonetheless opted out, then we might say that those who become infected consented to the risks involved and are thus responsible for their own illness. What should we think, however, about scenarios where harm occurs to those who cannot be safely or effectively vaccinated – e.g. vulnerable groups such as infants and the immunosuppressed? These groups are often at the highest risk of severe harm, and depend upon herd immunity (resulting from high vaccination rates) to protect them from vaccine-preventable infections. Members of such groups bear the burden of others’ freedom to opt out of vaccination, and this can cost them their lives. In 2015, for example, an immunosuppressed woman died in the United States during a measles outbreak made possible by a lapse in local vaccination rates[1].

Our recent article in the Journal of Medical Ethics argues that imposing risks of infection on others without good justification is morally blameworthy–and that individuals who opt out of vaccination are thus morally responsible for resultant harms to others. In defence of this thesis we address numerous important questions, and our answers may have significant implications for public health policy.

Should those who refuse vaccination be considered responsible even if they do not intend to harm others? We argue that they should, at least if vaccines are easily available and they have been adequately informed about the risks of transmitting disease to others. In any case, there are many situations in which we consider (and hold) people responsible for unintended harms that result from their imposition of risk on others.  Consider, for example, reckless driving.

Are the risks imposed by each non-vaccinator morally significant? Yes, because although the risk is small each time they have contact with those who are vulnerable, this risk is run very many times in a lifetime, and the consequences can include death. Interestingly, there is a strong element of moral luck here, since while all non-vaccinators impose similar risks, only some end up in chains of infection leading to infection of those who are vulnerable. We thus distinguish moral responsibility for conduct (i.e., refusal of vaccination) from moral responsibility for harm (that results from refusal of vaccination).

Should we consider vaccination morally obligatory, or merely supererogatory? In other words, should one be expected to endure vaccine side effects in order to protect others from harm? We argue that one should, since–like duty of rescue cases–the risks of vaccination are very low, but the benefits to others are highly significant (i.e., potentially life saving).  Furthermore, vaccination usually involves a net benefit, rather than a net harm, for those who are vaccinated[2]

An especially interesting and difficult question concerns the nature of individual responsibility for harms resulting from the collective action of those who refuse vaccination. If just one person refused vaccination in a population with strong herd immunity she would only very rarely end up in a chain of transmission to vulnerable others. But when many people opt out of vaccination, the probability that each will be involved in a chain of transmission increases significantly.

How should we think about the responsibility of each person in the chain? Is the last person (she who directly transmits to a vulnerable other) any more responsible than the first? There may be practical reasons for holding the last person entirely responsible, but in many important respects she is no more blameworthy than any other person in the chain. There are numerous challenges to apportioning blame among all intentionally unvaccinated transmitters in a chain of infection. Each person’s contribution to overall risk may be slightly different (e.g. because some may take more infection control precautions than others), and the ultimate risks of one’s actions (e.g., refusal of vaccination, failure to wash hands, contact with vulnerable persons, etc.) are contingent upon the actions of many others. Is there some quantum of blame for eventual harms that could, in theory at least, be accurately attributed to each non-vaccinator? We discuss possible ways of handling such questions in greater detail in our article, yet in many cases we can only find partial solutions and paths for further inquiry.   It is here noteworthy that the burgeoning philosophical literature on collective responsibility (e.g. in the context of climate change) may be highly relevant to vaccination ethics.

If non-vaccinators are responsible for harms to others, finally, are there any morally permissible options for those who wish to opt out of vaccination? One option would be for them to live as hermits, eschewing all contact with other human beings – if the isolation is total, the risk of harm to others will be zero. If this sounds too onerous, remember that sometimes the only way the immunosuppressed can avoid infection (and thus life-threatening illness) apart from herd immunity is to reduce or eliminate their contact with non-immune others. Another option would be controlled infection – those who wish to be exempt from vaccination could opt to be infected with the relevant pathogen and remain in isolation until they are (immune and) no longer contagious. In our paper, we suggest that, at the policy level, it may be practically realistic and morally justified to impose additional taxation on those who opt out of vaccination, with the additional funds used to support health programs for those who cannot be vaccinated for medical reasons.