Background on vaccine mandates for health or aged care workers

In healthcare settings, it is well established that vaccines significantly contribute to reducing various kinds of healthcare-associated infections, both viral and bacterial. For the latter, vaccines may have a secondary benefit for the problem of antimicrobial resistance by reducing the need for antibiotics.

The two main benefits of vaccination—illness and contagion prevention—are particularly relevant in the case of HCWs, although they provide different types of justification for vaccination requirements.

Preventing illness is obviously directly beneficial to the HCWs themselves. However, it also benefits the health system and the patients indirectly by reducing the risk of shortage of staff in healthcare settings, an ongoing problem during this pandemic. The probability of developing serious illness depends both on individual risk factors (age, underlying health conditions, obesity, previous infection) and degree of exposure. For instance, in the case of COVID-19, HCWs and other so-called ‘essential workers’ are at higher risk of severe illness than workers considered ‘non-essential’.6 The direct benefit of immunity is evident, but the indirect benefit is even more widely enjoyed. Particularly where the requirement to isolate is based on positive tests rather on the presence of severe symptoms, the vaccine may be beneficial in preventing staff shortage even in those at low risk of serious illness.

In January 2022, several hospitals in the UK declared ‘critical incident’ status caused by isolation requirements of staff infected with the Omicron variant. In the week before Christmas 2021, the absence rate of National Health Service (NHS) staff was 8%, compared with a 5% average absence rate in winter months pre-COVID-19.3 Influenza typically does not pose this problem to the same degree, since there typically is no routine testing for influenza and therefore no isolation requirement for staff. But in some influenza seasons staff shortages can happen as large numbers of staff fall ill and are unable to work. There is also the opposite problem of ‘presenteeism’, where staff with influenza or influenza-like illness attend work, thus increasing the risk of nosocomial infection.7 Both problems could in principle be addressed by reducing the risk of infection in HCWs in the first place. With COVID-19, the widespread use of testing combined with isolation requirements and the presence of a highly transmissible variant like Omicron made the risk of staff shortages higher.

The second benefit of vaccination for HCWs is the potential reduction of serious harm to patients. Public Health England estimates that during the first wave of COVID-19 (beginning February to end of July 2020), 20%–25% of COVID-19 hospitalisations may have been nosocomial.8 In Scotland, 30% of ‘COVID-19 deaths’, defined as deaths within 28 days of a positive COVID-19 test in 2020, were considered ‘definitive hospital onset’.9 10 The real figures may be higher.

However, while COVID-19 infections have obviously attracted a lot of attention in the past 2 years, COVID-19 is by no means an exception. The lack of routine testing for influenza infection makes it difficult to estimate how many patients catch the influenza in hospitals or care homes every year. The number is not insignificant. For instance, genetic sequencing of influenza samples suggested 15% of patients hospitalised with influenza at London University College hospitals during the 2018–2019 influenza season had a nosocomial infection.11

Vaccine mandates are typically controversial as they entail limitations of individual liberties for the sake of the collective good. There is a reasonable disagreement about the extent to which one person should be required to do things to prevent harm to others or even to contribute to collective goods from which they themselves benefit.12 Different political and ethical sensitivities would weigh individual rights against the collective good in different ways.

However, when it comes to HCWs, liberty-based counterarguments are more difficult to apply. Quite simply, HCWs have an ethical and professional obligation not to harm patients, or to minimise the risk of harm to patients, which other people do not have. What such obligations include—and whether they include vaccination—depends in part on the standards of negligence, as determined by the majority of professional bodies’ opinions. Normally, they do include vaccination or equivalent safeguards. For instance, the Department of Health in the UK recommends health clearance for tuberculosis, hepatitis B and C, and HIV for new HCWs who will perform exposure-prone procedures. The reason is ‘not to prevent those infected with […] viruses from working in the NHS, but rather to restrict them from working in those clinical areas where their infection may pose a risk to patients in their care’.13

This approach is typically reflected in the guidance about vaccination for healthcare staff by medical associations. In the UK, the code of Good Medical Practice states: ‘You should be immunised against common serious communicable diseases (unless otherwise contraindicated)’.14 The reason offered is the prevention of passing diseases on to patients. Some Australian states, such as Victoria, also introduced vaccination requirements for healthcare staff before the COVID-19 pandemic. But the need to guarantee adequate healthcare by preventing staff shortage due to illness also features in medical codes. For instance, in September 2021, the American Medical Association called for mandatory COVID-19 vaccination of HCWs as it is ‘needed to sustain the health system into the future as we learn to live with COVID-19’⁴.

Thus, a vaccine mandate for HCWs would be consistent with already existing professional requirements based on preventing harm to patients. However, a legally enforced mandate is different from a professional obligation and it requires additional justification. Not every professional obligation is also a legal requirement. In the next section, we provide three criteria that determine the ethical acceptability of vaccine mandates for HCWs: the criteria pertain to (1) risks of the vaccines, (2) benefits of the vaccines and (3) the availability of less restrictive alternatives to achieve comparable benefits. Criteria 1 and 2 are relevant to determining whether the risks of vaccination are proportionate to its benefits. Criteria 2 and 3 are relevant to determining whether the level of freedom restriction involved in a vaccine mandate is proportionate to its benefits.

Criteria for the acceptability of vaccine mandates for HCWs

COVID-19 vaccine mandates? Probably no

HCWs are at a higher risk of COVID-19 infection and death than the general population and COVID-19 has significant workforce implications, particularly without vaccination.19 High infection rates among staff have other undesirable consequences, such as an increased fear in people of contracting COVID-19, which can prevent them from attending healthcare settings and lead to higher morbidity and mortality from other diseases because of late or missed diagnoses.20

While these considerations weigh in favour of a COVID-19 vaccine mandate for HCWs, there seem to be, in the present context, stronger reasons against. We will see how COVID-19 vaccine mandates fare with regard to the three criteria identified above.

Influenza vaccine mandates? Probably yes

Although the focus of public health policies over the last 2 years has been on COVID-19, influenza represents a significant public health threat. For example, in the 5 years before the COVID-19 pandemic in England, influenza caused on average more than 11 000 annual deaths, with over 22 000 deaths in the 2017 and 2018 season.1 Most such deaths occur in people over 65 years, as a weaker immune system means that serious complications of influenza such as pneumonia are more likely and the immune response to the vaccine is poorer.39 And of course, the elderly and those with significant comorbidities and/or a weak immune system are over-represented in hospitalised patients.

In the 2020–2021 season, 76.8% of front-line HCWs were vaccinated against influenza in England, with uptake in NHS Trusts ranging from 53.0% to 100%.4 In the UK, there is no influenza vaccination requirement for HCWs as a state policy. This is in line with many other countries’ policy. For instance, in the USA no state requires influenza vaccination for HCWs as a condition of employment. Some states require employers to offer vaccination to their healthcare employees and some require them to report their employees’ vaccination status, but employees can be exempted for medical or religious reasons in some of these states and for any reason in the others. However, some individual organisations in the USA do require influenza vaccination as a condition of employment.

Are vaccine mandates discriminatory and coercive?

We have assessed the ethical proportionality of a vaccine mandate—balancing risks, benefits and the restrictiveness. However, some might think that mandates in the form of conditions of employment are unjustifiable in principle, regardless of proportionality. In particular, vaccine mandates might be considered unfairly discriminatory and/or excessively coercive.

We will examine these two considerations separately.

In one sense, discrimination means, quite simply, treating different individuals differently. It is not ethically problematic in itself. In another, normative sense, discrimination is often used to mean ‘unfair discrimination’, that is, when individuals are treated differently on the basis of factors that should not be considered relevant. Thus, in the first, unproblematic sense, all conditions in employment contracts exclude from employment individuals who do not fulfil certain requirements. Vaccination requirements are in a sense not different from requirements to (for example) provide evidence of visa status, copies of qualifications, proof of address and police checks, and so on.

The relevant question is whether it is unfair to require vaccination. This would be the case if vaccination were an ethically irrelevant factor for employment, if vaccination status became a ‘protected characteristic’ that should not create any form of disadvantage in employment decisions (in the way, for example, disability and gender are), if individuals could not access vaccines (thus being excluded from jobs for factors beyond their control), or if the level of coercion involved were excessive.

Vaccination status is an ethically relevant factor when it significantly reduces the risk of infection and contagion. Such reduced risk allows HCWs to fulfil their professional responsibility to minimise the risk of harming patients and to benefit them, as well as healthcare systems’ responsibility to provide adequate healthcare by minimising the risks of shortage of staff.

At the moment, vaccination status is not a protected characteristic, although we do not exclude that it might qualify for this (eg, if vaccination status were taken to express one’s core ethical or religious beliefs). This is a question we are not addressing here. We will simply proceed on the assumption that it is not a protected characteristic, bearing in mind that this might well change.

It would be discriminatory to exclude HCWs if they were unable to access a vaccine (because of cost or availability) or because of a true medical exemption. However, in virtually all settings where a mandate might apply vaccines will be easily available (often at no cost) to HCWs. Those with true medical exemptions should be exempted from vaccination requirements, although in such cases alternative precautions should be adopted (eg, the use of masks and regular testing for asymptomatic infection, if available) if necessary to protect patients.

So the question that remains to be addressed is about the level of coercion involved in vaccine mandates for HCWs: are vaccine mandates coercive and, if so, is the level of coercion ethically acceptable?

All conditions in employment contracts ask future employees to choose between their job and whatever is required. For example, HCWs already agree to health and safety requirements such as washing of hands or wearing gloves and masks when providing (certain forms of) patient care. There is no serious question that an HCW who declined to wash hands (or wear masks/gloves) should not be eligible to provide direct patient care. If this is a form of coercion at all, it is an acceptable one. The problem seems to arise when requirements affect health and lifestyle choices which have broader implications affecting one’s life as a whole. In such cases, arguably the level of coercion is higher. Vaccine mandates fall in this category. However, whether they are excessively coercive depends in part on how one understands coercion.

On so-called non-normative accounts, coercion is what reduces the options available to someone by making them unreasonable, given the magnitude of the penalties for non-compliance or, on some accounts and more controversially, the incentives for compliance.57 On such views, vaccine requirements of HCWs are coercive because they reduce the options available to those who refuse the vaccines. The degree of coercion involved will depend in part on the extent of the costs associated with giving up the option of a career as an HCW. However, on normative or ‘moralized accounts’,58 coercion only occurs when threats of penalties remove options to which individuals have a right to, or in any case that have some particular moral value. In this sense, to the extent that alternative career paths are available, vaccine requirements for HCWs are not coercive: there is no right to become an HCW and there are plenty of professions (or perhaps specialisations within the healthcare profession) that do not require vaccination as a condition of employment. On this view, a vaccine mandate is no more coercive than any other condition of employment because someone can refuse the vaccine and choose another profession.

However, those who adopt non-normative accounts of coercion can claim that mandates are coercive, and they may note that the costs associated with giving up a career as an HCW are extensive. In particular, alternative career paths are not always easily available, as it presumably is not easy for someone to switch career after having been in the profession for some years. This sounds reasonable: the mandate might not be very coercive for someone who needs to decide whether to become a healthcare professional and knows that that option comes with a vaccination requirement, but it can be very coercive for someone who is already a professional (and entered the profession on the understanding that the vaccine they would rather not take was not mandated). Thus, one way to reduce this coercive pressure and strike a balance between individual freedom and patients’ interests is to make vaccination a condition of entry into the profession rather than mandating those already employed, and adopt a conditional mandate if at all possible for those already in the profession. This is because while someone can relatively easily choose a different career path when young and deciding whether to become a healthcare professional, it is way more difficult, or perhaps an unreasonable option, for someone in their 40s or 50s to switch career because of a new condition of employment that they never agreed to. Whether this level of coercion on someone already in the profession is ethically impermissible depends on whether it is reasonable to expect new health professionals to take future, as yet not developed, vaccines. If that is a reasonable expectation, then again the level of coercion does not seem different from the one posed by any other condition of employment that sets future expectations for employees.

In any case, even if a vaccine mandate places no more coercive pressure on an individual than other conditions of employment, some may regard it as more problematic because of the right it over-rides. Arguably, the right to bodily integrity or bodily autonomy (understood as a right to refuse physical interventions on the body) is a fundamental freedom. We might thus only be willing to accept a lower degree of coercive pressure when this right is at stake, compared with the degree of coercive pressure we accept when other lesser claims are at stake. To illustrate, those who take this view may see a vaccine mandate as problematically coercive where mask/glove/handwashing mandate for HCWs would not in so far as the former infringe upon the right to bodily integrity, but the latter would not. If this is the case, then the permissibility of a mandate will turn on the (1) extent of the coercive pressure that we are willing to accept with respect to interventions that interact with the right to bodily integrity, and (2) the degree of coercive pressure involved in a mandate. Our own view is that if different career choices are easily available (and that is a significant ‘if’), a vaccine mandate need not involve a degree of coercive pressure that would entail an infringement of the right to bodily integrity.

Ultimately, there is an ethical balance to be drawn between protecting patients (including their own right to not acquire serious but preventable nosocomial infections) and coercing some healthcare professionals into having a vaccine that they would prefer not to receive. The harm prevented should be great enough and the risks to professionals small enough to make the coercive pressure justified.

The analogy with conscientious objection

The balance between patient well-being and professional freedom involved in vaccine mandates for HCWs is similar in important respects to the case of conscientious objection in healthcare. The above suggestion of introducing a requirement as a condition of employment may also apply in this context. According to certain views, freedom of conscience is permissibly infringed upon when conscientious objection is ruled out by job contracts, as long as there is a reasonably available option to choose a different profession. This is because the right to freedom of conscience is a qualified one. It is legitimate to make employment subject to eligibility criteria that ensure that professional obligations are discharged. On such views, healthcare professionals do not have a right to conscientious objection where that would violate professional duties, including the duty of beneficence and non-maleficence.59

Arguably, such view is questionable and indeed many would not agree. However, even those who think that this line is too strong and are in favour of some form of conscientious objection in healthcare tend to think that conscientious objection should be constrained, for example by requiring a duty of referral and a duty to provide the medical intervention in emergency cases.60 This is because patients’ medical interest is taken to normally have priority over personal moral views of healthcare professionals.

Similarly, HCWs might be opposed to vaccines on personal moral or religious grounds. However, putting patients’ interests first means that professional and contractual obligations to avoid causing harm potentially trump those personal beliefs. It is not clear that the exemptions that allow health professionals to conscientiously object as long as a colleague is available to provide the contested service can be extended to non-vaccination for HCWs who have close patient contact. Every interaction means an increased risk of infection to the patient compared with a situation where the HCW is vaccinated.

Thus, a conditional mandate with redeployment to non-patient-facing roles (as per the proposal above) would appear to be the closest equivalent.

Conclusions: implications for vaccine mandates more generally

Recent debates and policy decisions relating to vaccine mandates for HCWs in the setting of the COVID-19 pandemic might be taken to set a clear precedent for future vaccines. In countries that have adopted such a mandate, the door might now be open for wider application. Given political and apparent ethical support for such mandates, it may be inevitable that countries like Australia, USA, and others will review their approach to influenza vaccination in the coming winters. Alternatively, countries that have taken the opposite approach might be seen to have foreclosed this option. For instance, UK’s former Health Secretary Jeremy Hunt expressed⁷ his view that the scrapping of the COVID-19 vaccine mandate will make it hard to justify other vaccine mandates in the future.

However, in this paper we have suggested that while the ethical principles that support vaccine mandates for HCWs remain constant, circumstances and characteristics of viruses, diseases and vaccine differ. The same principles and criteria can justify mandates for certain vaccines and not for others. Here, we have argued that, given current evidence, they justify influenza vaccine mandates, but not COVID-19 vaccine mandate.

This might sound counterintuitive given that the COVID-19 pandemic has certainly caused substantially more deaths and morbidity than seasonal influenza. Current estimates suggest that it has caused 20 million excess deaths—substantially higher than annual influenza deaths (300 000–600 000).61 However, for reasons that we have given above, the balance of risks and benefits suggests that an influenza vaccine mandate, but not a COVID-19 mandate, would currently be ethically proportionate. The same considerations would support mandates for HCWs for other vaccines that offer equivalent prevention of harm and at similar risk to individuals, such as hepatitis B.

Mandates should be introduced on a disease-specific and vaccine-specific basis. The problem must be a significant one, the vaccines must be safe and effective at preventing illness and/or transmission, mandatory measures must be superior to less coercive alternatives, and the costs in loss of liberty and risk to health professionals must be proportionate in professional terms to the benefits to patients. In box 1, we provide a proposal for ethically assessing contractual vaccine mandates in healthcare.

In the case of new vaccines, mandates should be avoided at early stages, while risks are unclear, and be replaced by alternatives (such as testing and protecting personal equipment requirements) or other means to encourage uptake, such as some form of incentives (financial or non-financial). In those cases, contractual (conditional) vaccine mandates should only be considered if alternatives do not offer enough protection from nosocomial infection and there is sufficient evidence around their relative safety, bearing in mind that it is reasonable to expect HCWs to take on themselves some higher degree of risk for the sake of protecting patients than the general population.