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Vaccine 26 (2008) 5562–5566
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journal homepage: www.elsevier.com/locate/vaccine
The ethics of mandatory vaccination against influenza for health care workers
J.J.M. van Deldena,∗, R. Ashcroftb, A. Dawsonc, G. Marckmannd, R. Upshure, M.F. Verweijf
aUniversity Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
bUniversity of London, Queen Mary School of Law, Mile End Road, London, United Kingdom
cCentre for Professional Ethics, Keele University, United Kingdom
dDepartment of Medical Ethics, University of Tuebingen, Germany
eJoint Centre for Bioethics, Research Chair in Primary Care Research Unit, University of Toronto, Canada
fEthics Institute, Utrecht University, The Netherlands
a r t i c l ei n f o
Received 10 April 2008
Received in revised form 18 July 2008
Accepted 4 August 2008
Available online 21 August 2008
a b s t r a c t
Vaccination of health care workers (HCW) in long-term care results in indirect protection of patients who
are at high-risk for influenza. The voluntary uptake of influenza vaccination among HCW is generally
low. We argue that institutions caring for frail elderly have the responsibility to implement voluntary
programmes for vaccination against influenza of HCW. When uptake falls short a mandatory programme
may be justified. The main justification stems from the duty of care givers not to harm one’s patient when
one knows there is a significant risk of harm and the intervention to reduce this chance has a favourable
balance of benefit over burdens and risks.
© 2008 Elsevier Ltd. All rights reserved.
Many think of influenza as a trivial disease. However, this is cer-
tainly not the case, at least among the elderly population, where
up to 90% of influenza-associated mortality, directly or indirectly,
occurs. There will be considerable season-to-season variability, but
the incidence of hospital admissions has been reported to be 10%
and mortality rates to exceed 5% . Vaccination against influenza
infections of the elderly may reduce morbidity, mortality and hos-
pital admission rates, but the response of the immune system of
the elderly is generally weaker, resulting in a protection of 50–70%
of the population at best, even after being vaccinated. Therefore,
in spite of high compliance with vaccination, the risk of influenza-
related complications among patients who are often both frail and
elderly, is particularly high and the possibilities for the individual
patients to protect themselves are limited.
Vaccination of health care workers (HCW) in long-term care
facilities results in indirect protection of patients who are at high-
effect on the continuity of care and research has shown that vac-
cinating the personnel reduces influenza infections and therefore
less working days are lost . The costs per life year gained of vac-
cinating HCW are low . On these grounds some organisations
∗Corresponding author. Tel.: +31 88 755 9361; fax: +31 88 755 5485.
E-mail address: firstname.lastname@example.org (J.J.M. van Delden).
have issued guidelines in which influenza vaccination of HCW is
tiatives of countries to administer influenza vaccination to health
care workers in contact with high-risk persons .
In spite of these recommendations the uptake of influenza
vaccination among HCW in response to voluntary vaccination pro-
grammes is generally incomplete. One may ask therefore whether
it is necessary and morally justifiable to impose a mandatory vacci-
nation programme. Such a mandatory policy raises several ethical
issues. It is one thing to speak of a general duty of beneficence of
HCW, but is not clear that this implies a duty to accept vaccina-
tion. One could also argue that given the respect due to autonomy,
HCW should not be pressured to be vaccinated. Moreover, HCW
might consider it unreasonable if they are expected to be vacci-
nated themselves for the sake of others. The aim of this article is
to discuss some of these important ethical questions and to draw
a conclusion about the justifiability of mandatory vaccination. We
focus our discussion on vaccination of HCW in long-term care facil-
ities. By HCW we mean all those who have contact with residents,
be it as a professional providing direct care or otherwise.
2. Is the efficacy and cost-effectiveness of HCW vaccination
In two British randomized trials the effectiveness of HCW vac-
cination was studied [2,9]. A rise in vaccination rates among the
HCW resulted in a relative reduction of mortality among patients
0264-410X/$ – see front matter © 2008 Elsevier Ltd. All rights reserved.
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J.J.M. van Delden et al. / Vaccine 26 (2008) 5562–5566
of about 40%, but the incidence of influenza-like illness did not
change. These results have led some to conclude that vaccination
of HCW has considerable (indirect) effects on the health of patients
. However, the authors of a 2006 Cochrane meta-analysis con-
cluded that there is no evidence that vaccination of healthy people
under the age of 60, who are HCW caring for the elderly, affects
influenza complications in those cared for . However, a more
recent cluster randomized trial demonstrated a decrease in mor-
tality through the vaccination of HCW (rate difference −5.0 per
100 residents) as well as a reduction in morbidity . According
to the Dutch Health Council this study has proven the effective-
ness of indirect protection . However, the indirect benefits of
influenza vaccination may be less impressive when compared to
enhanced hygiene. Of course this should be subject to further
research . In addition, the effectiveness of a mandatory pro-
gramme is not necessarily the same as of a voluntary one . Yet,
it would seem that there is strong evidence to support the com-
mon sense view that influenza vaccination of HCW in long-term
care institutions reduces the probability of death and morbidity
In addition, any vaccination programme, be it voluntary or not,
needs to be cost-effective, meaning that a sufficient amount of
health benefit results from the money spent. An economic eval-
uation in the United Kingdom context showed that HCW influenza
vaccination might be cost saving, and in the ‘worst-case scenario’
only cost £405 per life year gained . It is plausible to assume
that the cost-effectiveness of HCW vaccination in many other high-
income countries would be similar.
3. Have strategies to raise voluntary uptake of vaccination
been sufficiently demonstrated to fail?
As stated above, based on the evidence described several pro-
fessional organisations have advised vaccination of HCW. This is
likely to have only a limited effect on vaccine uptake. For instance,
1year after the introduction of the 2004 guideline of the Dutch
Society for Nursing Home Physicians the proportion of vacci-
nated HCW had risen from 5–8% to 10.5% only . Even where
campaigns to increase uptake accompany voluntary programmes
vaccination usually remains incomplete. Several strategies have
been advocated: information and education; free and easy access
to vaccination; programmes that do not require vaccination but
do require a justification for not taking it. Of these methods, easy
access to free vaccine and an educational programme, result in the
highest uptake . Yet, even here two main barriers to vaccine
uptake were consistently reported: (1) misperception of influenza,
its risks, the role of HCW in its transmission and the importance
and risks of vaccination and (2) the lack of available vaccination
. In the Netherlands Looijmans et al. have studied which pol-
icy, behavioural and demographic determinants predict influenza
vaccine uptake among HCW in Dutch nursing homes . This
study showed that modifiable health belief factors are predictive
for influenza vaccine uptake among HCW. Both studies imply that
vaccine uptake can be significantly raised by combining several
interventions in a vaccination campaign. Arguably, the possibilities
for improving voluntary programmes are not yet exhausted. It is
also important to realize that in order to be effective (i.e. reduce
mortality and morbidity) vaccine uptake among HCW does not
need to be 100%. In the studies by Carman and Hayworth vacci-
nation rates in the intervention institutions varied between 50.9%
and 43.2% [1,2]. Apparently, you do not need herd immunity to
have population effects: even a relatively modest increase in vac-
cine uptake may have a significant impact on the health of nursing
4. Who should act upon this data?
At present there is evidence for the efficacy of vaccinating
HCW in long-term care institutions for the elderly such as nurs-
ing homes. Vaccination of nursing home HCW leads to a significant
reduction of the risks for residents. Health care institution boards
have a moral obligation to reduce avoidable risks for persons
within the institution. Therefore, they ought to implement vol-
untary vaccination campaigns directed at HCW who during their
work are in close contact with residents. The form of this cam-
paign should be tailored to the institution and take into account
the results of studies such as those cited by Hofmann and per-
formed by Looijmans. It remains possible though that vaccine
uptake even with a state-of-the-art voluntary campaign does
not result in a vaccine uptake of over 50%. The next question
then is: would it be defensible to introduce mandatory vaccina-
5. What is meant by mandatory vaccination?
To speak of mandatory programmes may be misleading. No
one will suggest that HCW should be vaccinated against their
will by force. Most so called mandatory programmes in reality
are conditional, in the sense that objectors are refused the abil-
ity to work either completely or temporarily. A further question
in the latter case is whether salary should be paid for the days
off work. We think that question can be put aside because the
strategy of temporarily limiting access to the institution is diffi-
cult to implement and ineffective to a large extent. For example,
it will be hard to know exactly when access should be denied:
when the HCW gets ill? Or when the first patient shows flu-
like symptoms? Or only when there is a local epidemic? It is
less effective because transmission may occur in the presymp-
tomatic phase of an infection and during subclinical infections.
Paradoxically, a hard-working ethos might increase the risk of
infecting a patient. Therefore, when we speak of a mandatory pro-
gramme we mean a conditional one in which yearly vaccination
is considered to be a requirement for the job. Can such an institu-
tional programme be defended ethically? Below we discuss three
arguments in favour and four against this kind of mandatory vac-
6. Arguments in favour of mandatory vaccination
6.1. The duty not to harm others
Generally speaking people have a moral obligation not to harm
each other. When infecting someone else could have been pre-
vented, but is not, this can be regarded as harming that person .
This is relevant not only in cases where one knows oneself to be
infected (e.g. HIV-positive persons), but also when one is not aware
be prevented by taking general preventive measures, like washing
one’s hands. This does not imply an obligation not to become ill,
but does lead to a prima facie duty not to infect someone when one
knows this can be prevented.
Verweij argues that this duty could be overdemanding for indi-
viduals . Persons who carry a communicable disease could for
instance be expected, on a very strict interpretation of this duty, to
completely isolate themselves from others. Some possible limits to
what can be reasonably expected from someone would be where
the burden of taking the preventive measure would outweigh the
benefits for others or if a measure would involve significant risks
for the vaccinated person. So we have to discuss the burdens, the
benefits and the risks of vaccination.
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J.J.M. van Delden et al. / Vaccine 26 (2008) 5562–5566
Generally speaking the physical burdens of influenza vaccina-
tion are low, even given the fact that it has to be repeated each year.
In a mandatory programme the imposition should count as a bur-
With respect to the potential benefits of influenza vaccination
we must determine whether the harm can be prevented with cer-
tainty. In principle there is no such certainty as the vaccine will
always be less than 100% effective and even less so in years in
which there is a mismatch between vaccine strain and circulating
strain. Hence, HCW are vaccinated in order to reduce the probabil-
ity of becoming infected on a population level. We argue that the
resulting obligation to undergo vaccination is weaker than in direct
causal relations but still present. On the population level we think
With respect to the risks involved, most adverse reactions to
influenza vaccination are relatively minor with the notable excep-
tion of some very rare occurrences of vasculitis, encephalomyelitis
neuritis and Guillain-Barré syndrome [7,18,19]. Even though such
risks are rare, fairness requires that any mandatory programme
should be accompanied by a damage compensation scheme.
On balance we hold the view that the duty not to infect others
holds in the case of influenza as the considerable benefits for the
on behalf of the HCW, at least for persons who work closely with
persons for whom influenza poses a great risk.
6.2. Special obligations for health care workers
since health is a primary value in health care. It is the responsibility
of health care workers to be attentive to the needs of the patients
entrusted to them and to factors that may compromise their health
to a certain extent also holds for non-professional HCW (e.g. vol-
unteers) who work in a nursing home, but this point is beyond the
scope of this paper. Patients not only have an expectation that their
of care to the residents . It seems reasonable to hold that such
a duty will require more than a general duty not to cause harm. In
case of HCW in a nursing home or home for the elderly an addi-
tional professional responsibility is mentioned by Van den Hoven
not to undermine the goal of the institution. Many nursing homes
have a policy of vaccinating all non-refusing residents in order to
protect individuals and create herd immunity. HCW vaccination is
an additional strategy to reach this goal. Moreover, by taking the
Also, Poland points to the possibility that public trust in the
forgoing vaccination thus failing to prevent serious consequences
for their patients .
One could argue that these obligations are not relevant since
a HCW refusing vaccination does not know for sure that he will
terargument is mistaken however. Knowingly running the risk of
infecting anyone of your patients if this could have been prevented,
amounts to a culpable omission and violates the duty not to infect
others and the duty to care.
One could also argue that it is one thing to expect HCW to pro-
vide benefits for patients and to expect them not to directly harm
them (for instance by taking measures to prevent mistakes with
medication), but it is quite something else to expect HCW to harm
themselves in order to benefit their patients. The latter cannot be
justified on any account of professional responsibility, according to
This would seem to be a reasonable position if indeed harm
would be involved. However, to describe the influenza vaccination
as a harm, even if it has to be taken annually, seems implausible.
Yet, some will see vaccination as a harm indeed: the conscientious
objector. To him we will turn shortly.
Often persons who are identified as eligible for influenza vacci-
nation, such as nursing home residents, are persuaded by HCW to
take the vaccination—if not for their own sake, then at least for the
sake of their fellow patients. It would be inconsistent for the HCW
7. Arguments against mandatory vaccination
7.1. Freedom of choice of HCW
Above we mentioned mandatory vaccination as a burden
because of the infringement of one’s autonomy. But even when
an individual HCW does not have strong opinions about being
straints to personal autonomy and freedom of choice. The least one
can say is that a strong justification is needed for such constraints.
Such a justification would seem to follow from the serious effects
an influenza infection may have on the frail elderly. Generally the
prevention of harm to others is considered a legitimate cause for
constraints on autonomy. The problem however is: can contamina-
tion with the flu really be said to be a harm? As Verweij points out,
not any setback to interests is to be considered as harm . For
that, the setback has to be the result of an action (or omission) that
is wrongful. According to Verweij foregoing vaccination will only
be considered morally wrong if this involves considerable risks to
others and if vaccination would significantly reduce those risks. In
the case of frail elderly this might however precisely be the case.
Hence the argument of harm to others would seem to justify some
limitation of autonomy for those caring for the frail elderly.
Obviously, it would be morally superior if sufficient vaccination
rates could be reached with voluntary influenza vaccination pro-
grammes. The principle of subsidiarity requires that participation
in a vaccination programme should be voluntary unless mandatory
vaccination is necessary to prevent otherwise unpreventable seri-
ous harm and voluntary programmes have proven to fail [24,25].
7.2. There are alternatives to mandatory vaccination programmes
Some have expressed the view that alternative programmes
aiming at enhanced hygiene could be equally effective in reducing
have not been performed.
7.3. Mandatory programmes may lead to opportunity costs
Institutions mandating immunization of HCW may find
resources consumed with tracking persons who do not comply
with the programme . These opportunity costs may limit the
resources available for education and free access to vaccinations.
However, the same argument could also be used as an argument
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J.J.M. van Delden et al. / Vaccine 26 (2008) 5562–5566
pro mandatory vaccination. Performing time-consuming educa-
tional programmes to increase voluntary vaccination uptake may
diminish opportunities in terms of time available for normal care.
7.4. Vaccination is only in the interest of the employer
Budget reductions for nursing homes have forced employers to
reduce the nursing staff on the wards, at least in the Netherlands.
usually have organised programmes to reduce absenteeism. Vac-
cination against influenza therefore might be perceived to be in
the employer’s interest. However even if there is some truth to the
only. HCW vaccination protects the health of residents. Moreover,
if vaccination also leads to a reduction of absenteeism, this is not
8. What place for conscientious objectors?
Arguments from conscience or philosophical objection have a
long tradition in the debate about mandatory vaccination. Consci-
entious objection was created in British common law in 1916 for
resistance to small pox vaccine . These objections are arguably
protected under the Siracusa Principles . For some, illness need
not always be a bad thing. In this view a period of illness can also
be an opportunity to restore the natural balance. Others may con-
sider the vaccination a considerable harm to their bodily integrity.
We think any mandatory programme should grant conscientious
objectors the possibility of refusing vaccination without any con-
sequences. While we consider it justified to require the objectors
to state the reasons for their objections, it doesn’t seem possible
to distinguish between legitimate and illegitimate reasons. There-
fore, we use the term “conscientious objectors” in a rather broad
sons to object to the vaccination. Yet, this policy will at least have
the benefit of requiring HCW to consider the consequences of their
omission in relation to vaccination. We estimate that the number
of conscientious objectors will be low. If that assumption is correct,
allowing exceptions for conscientious refusal will not significantly
reduce the effects of the vaccination programme.
In conclusion we think that long-term care institutions caring
for frail elderly have the moral responsibility to implement vol-
untary programmes for vaccination against influenza of HCW who
are in direct contact with these residents. Obviously, it would be
morally superior if voluntary influenza vaccination programmes
result in sufficient uptake. Thus, if voluntary programmes are able
tory programmes will not be necessary. However, when uptake
remains below this level a mandatory programme may be justified.
We think 50% at present is a reasonable and defensible thresh-
old given the present state of evidence, but if future studies show
a further reduction of morbidity and mortality with even higher
vaccination rates, this may have to be changed.
With a mandatory programme we do not mean forced vaccina-
to vaccination when they want to (continue to) work in the insti-
The main justification stems from the duty of HCW not to
harm a patient when one knows there is a significant risk of harm
through infection and the intervention to reduce this chance has a
favourable balance of benefit (effect) over burdens and risks. Such
a ‘harm to others’ argument would certainly justify some limita-
tion of autonomy for those involved in the care of the frail elderly.
Whilst we see a place for conscientious objection, this should not
be confused with ignorance or indifference towards the benefits
of greater uptake of influenza vaccine among persons working in
This article has been written on the initiative of the European
Scientific Working group on Influenza (ESWI), a multidisciplinary
group of key opinion leaders in influenza who aim to combat the
impact of epidemic and pandemic influenza in Europe. The views
expressed in this article are those of the authors.
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