Childhood immunization is one of the most important and cost-effective public health measures in our armoury. There is no doubt that immunization reduces the incidence and severity of infectious diseases and saves lives1−3. But vaccines are unique among public health measures, in that their administration occasionally causes injury. Should routine childhood immunizations be compulsory? In this paper we consider primarily those immunizations currently recommended in the Australian routine childhood schedule2.
Abstract: Routine childhood immunizations are compulsory in a small number of countries, including the United States of America. Arguments used to justify making immunizations compulsory include enhancing the health of the community and treating as paramount the rights of the child to be protected against vaccine-preventable diseases. But compulsory immunization infringes the autonomy of parents to make choices about child rearing, an autonomy which we generally respect unless doing so seriously endangers the child's health. We present a historical review and ethics discussion on whether routine childhood immunizations should be compulsory. We conclude that, for both ethical and practical reasons, routine immunization should not be compulsory if adequate levels of immunization can be achieved by other means.
Compulsory immunization: past and present
There is nothing new about compulsory immunization, nor about vociferous anti-vaccination movements. The British Vaccination Act of 1853 made smallpox vaccination compulsory for all infants in the first 3 months of life, and made defaulting parents liable to a fine or imprisonment4. This was the first time that public laws potentially infringed civil liberties, and the Act spawned an Anti-Compulsory Vaccination League and an anti-vaccination demonstration in Leicester attended by 100 000 protesters4. Vaccination rates fell and, in 1898, ‘conscientious objectors’ were excused from having their children vaccinated.
The United States of America has an even longer history of compulsory immunization. The State of Massachusetts introduced compulsory smallpox vaccination in 1809, while in 1922 the Supreme Court upheld laws requiring vaccination for school entry5.
Routine childhood immunization, against at least some infectious diseases, is compulsory in a number of countries, including Croatia, France, Italy, Poland, Slovakia and Taiwan. The United States of America has had school immunization laws, requiring compulsory immunization at entry to licensed day care and to school, for a number of years, although enforcement has been variable. In the 1970s unimmunized children were excluded from school during measles outbreaks. In 1977, a measles outbreak occurred in Los Angeles County. After immunizing thousands of students, 50 000 of the 1.4 million students remained unimmunized and were excluded from school. Most returned within days with proof of immunity, and the number of measles cases plummeted5. Recently there has been greater emphasis on enforcing immunization requirements at school entry. There is no national immunization law, all regulations being State-based. The exact requirements vary but all States require diphtheria, measles, polio and rubella immunization. Sanctions for non-compliance also vary, and some States threaten to take child care proceedings if there is persistent failure to immunize. Forty-eight of the 50 States allow exemptions for those with deeply held religious beliefs opposed to immunization, but only 15 States allow parents to decline immunization for ‘philosophic’ reasons5. It is argued that US school immunization laws mainly act as a safety net to ensure that under-privileged children are immunized, while offending ‘very few’, although up to 2.5% of students are exempted in States which allow philosophic exemption5.
Vaccines save lives; failure to immunize costs lives
The eradication of smallpox in the 1970s, by targeted use of smallpox vaccine, has not only prevented many thousands of deaths, but is estimated to have saved US$1.2 billion annually in the 25 years since the last case was reported3. Poliomyelitis has almost been eradicated from the world6.
More recently conjugate vaccines have reduced the annual number of cases of Haemophilus influenzae type b (Hib) infection, previously the commonest cause of meningitis in industrialized countries, by over 95%7. Most routine childhood vaccines protect against communicable diseases, which can be transmitted person-to-person, and which we will term transmissible. Immunization against transmissible infections, for example, diphtheria, pertussis, polio, Hib, hepatitis B, meningococcus, pneumococcus, varicella, protects the child, but also reduces spread to other children and adults, resulting in herd immunity (see below). Universal rubella immunization is a special case, where the direct benefit is primarily to persons other than the recipient, by reducing the incidence of congenital rubella syndrome. In contrast, tetanus immunization protects only the recipient, because tetanus is not transmissible.
It is sometimes argued that vaccine-preventable diseases are no longer as serious, and that modern medical treatment would prevent the high morbidity and mortality once seen. A recent example illustrates the fallacy of this belief:
The break-up of the Soviet Union caused enormous disruption to health services. As a result rates of childhood immunization fell drastically. Between 1991 and 1996 there was an outbreak of diphtheria, with over 140 000 cases notified and over 4000 deaths8.
Vaccine-preventable diseases remain life-threatening, and outbreaks will recur if immunization levels fall.
Immunizations can be harmful
Although the commonest adverse events following immunization are relatively minor and self-limiting, such as local reactions, fever and irritability, immunizations can occasionally cause severe irreversible complications and rarely, even death.
Vaccine-associated paralytic poliomyelitis (VAPP) is estimated to occur once in every 2.4 million doses of oral poliovirus vaccine (OPV)9. Measles vaccine causes an acute encephalitis with an incidence of one in a million doses, although in contrast the incidence of acute encephalitis after wild-type measles infection is about one in a thousand10. Yellow fever vaccine has caused yellow fever in a small number of recipients, and six deaths have been reported from fulminant yellow fever acquired from the vaccine11.
Risks versus benefit
We take calculated risks every day of our lives. Travel is a good example. The speed and convenience of road, rail and air travel mean that most persons accept the slight risk of an accident in favour of the benefits offered by quicker travel.
In general the benefits of immunization far outweigh the risks. The risk of vaccine-induced injury is hundreds to thousands of times lower than the risk of similar complications of the natural, wild-type infection1−3.
People who are afraid of harming their children by immunization tend to over-emphasize the risks of vaccine injury and to minimize the risk of wild-type disease2. This reflects a general tendency to be more worried about causing damage to one's child by doing something to them than by not doing it. This is referred to as the fear of commission rather than of omission2. In his autobiography, Benjamin Franklin wrote with tragic eloquence:
In 1736, I lost one of my sons (Francis Folger) a fine boy of 4 years old by the smallpox. I long regretted bitterly and still regret that I had not given it to him by inoculation. This I mention for the sake of parents, who omit the operation on the supposition that they should never forgive themselves if the child died under it: my example shows the regret may be the same either way, and that therefore, the safer should be chosen.
Public health and paternalism
Some public health interventions that have been shown to prevent injury or death have been made compulsory, because the public cannot be trusted to comply unless there is a degree of coercion. Examples include seat-belt legislation, motor-cycle helmets, bicycle helmets and swimming pool fences. Sanctions for disobeying regulations are usually fines, and possible loss of motor vehicle licence for frequent offenders regarding seat belts and motor-cycle helmets. Those who oppose such legislation do so for different reasons, such as because it is paternalistic, but they also try to argue that the intervention may itself be harmful. Seat belts can occasionally cause crush injuries to the chest or spine, and while being thrown from a car is likely to result in injury or death, being thrown out occasionally avoids injury, for example from fire. Helmets decrease the risk of head injury, but may rarely inflict damage. Those opposed to swimming pool fences even try to argue, contrary to the evidence, that pool fences may give a false sense of security and increase the risk of drownings.
Are the above public health interventions comparable to immunization, because the benefits outweigh the risks, or is immunization different? It seems to us that there is an important difference between immunization, which involves the injection of foreign material, even though with the intention of protecting the recipient and the community, and the compulsory use of seat belts, crash helmets or pool fences. Compelling someone against their will to have an immunization could be seen as constituting a physical assault, whereas the other interventions are substantially less invasive.
Herd immunity and the paradox of the ‘free riders’
Herd immunity is the phenomenon that, once a critical proportion of a population is immune to a particular transmissible disease, through infection or immunization, the disease can no longer circulate in the community12. The concept only applies to diseases such as diphtheria, measles and pertussis, which are confined to humans and transmissible person-to-person. If there is an animal reservoir, and no transmission from person-to-person, such as for tetanus or rabies, then an individual derives no benefit from the immunization of others in the community. An individual is only protected against tetanus if that individual is immunized.
The critical level of population immunization to achieve herd immunity varies from disease to disease. For Hib disease, rates fall rapidly once 85% of infants are immunized1,2. Measles requires approximately 95% immunization rates to stop any outbreaks2,3. Pertussis continues to circulate, although at much reduced intensity, even when high levels of immunization are retained; the reason is thought to be waning immunity in adults, who then infect babies. One major benefit of high rates of immunization is to protect, from diseases like whooping cough, babies too young to have been immunized (almost all whooping cough deaths are of babies under 3 months old)7.
An important implication of herd immunity is that failure to immunize a child against a transmissible infection may not only render that child susceptible to infection, but may imperil other children. Unimmunized school children in Colorado had a greatly increased risk of catching measles (22-fold) and pertussis (6-fold)13. In addition, pertussis outbreaks were more likely in schools with a higher percentage of unimmunized children12. Immunization against pertussis is not 100% protective, so fully immunized children were catching pertussis, and possibly transmitting it to their infant siblings, yet the pertussis was circulating largely because some of their fellow school children were not immunized.
When the population is highly immunized against a disease subject to herd immunity, then a parent may elect not to have their child immunized, and the child is protected by the herd. Such parents are sometimes referred to as ‘free riders’14. If the number of free riders increases, the population becomes more susceptible, and the disease will start to circulate.
What this description also illustrates is that the risk-benefit equation of immunization against a transmissible infection varies for any single child in the community according to community rates of immunization. If almost all other children are immunized, then a child can be unimmunized and benefit from herd immunity. If vaccine-preventable diseases like measles and pertussis are circulating, because of low levels of immunization, the benefit of immunization for any individual far outweighs the risk. A corollary is that immunization of a child against a transmissible infection protects the community as well as protecting that individual.
Arguments in favour of compulsory immunization
Communitarianism is a modern term for a philosophical theory that insists that we recognize the value not only of individual freedom but also of the common good15. Although communitarianism is a modern term, it is an ancient concept: philosophers such as Aristotle and David Hume espoused the importance of the community15.
A communitarian may well argue that immunization benefits the whole community and protects the common good of society, and that since its significance in protecting the common good outweighs its significance in limiting individual freedom, immunization should be compulsory. An extreme communitarian might say that everyone in the community should be immunized (unless there is a medical contra-indication) and that anyone who declined immunization was effectively declining to be part of the community and should be forced to leave the community. A moderate communitarian would find a less draconian sanction for non-compliance.
Consequentialists or utilitarians argue that actions or policies are good or bad according to the balance of their good and bad consequences. Compulsory immunization would be preferable to voluntary immunization if it produced the best overall result, from a perspective that gives equal weight to the interests of each affected party. Compulsory childhood immunization would almost certainly result in less disease and hence less suffering, which would outweigh vaccine adverse events. A bad consequence to consider, however, is the limitation to personal freedom occasioned by coercing people to immunize their children. If compulsory immunization caused concern about coercive government control, yet voluntary immunization could achieve almost equally high rates, then a consequentialist might prefer voluntary immunization. If compulsory immunization was the best way to protect children and was acceptable to the community, then a consequentialist should favour compulsory immunization.
(iii) Rights-based: rights of the child and the community
An advocate of children's rights may well argue that, because children need to be protected from dangerous infectious diseases, they have a right to the protection afforded by immunization16. Such a right, it might be argued, generates a duty on the part of parents (or, if they are negligent in the fulfilment of that duty, on the part of the state) to immunize the child. Since it is well known that some parents will be negligent with respect to this duty, the state must accept that it has the duty to ensure that each child is immunized, and if it is objected that parents have a right to decide how best to look after their offspring's health and well-being, the advocate of the child's right may well claim that the child's right to protection has priority over the parents’ right to decide.
A communitarian might say that the community's interests should take preference over individual rights. How do we decide which rights should be paramount: the child’s, the parents’ or the community’s? One answer is the degree of risk17. If the risk to the child or the community is high, then it may be necessary to over-ride the parents’ right to choose. A child bitten by a rabid dog will almost certainly die unless given rabies vaccination. If a parent refused rabies vaccination in this circumstance, the situation would be a child protection issue, and the child's right to protection would be the paramount consideration. This situation is analogous to a child of Jehovah's Witness parents who is bleeding to death: the child is too young to choose, and the child's safety becomes pre-eminent.
If there was an outbreak of a vaccine-preventable disease, which was devastatingly severe and children could not be protected simply by exclusion from school, it might be argued that compulsory immunization would be justified. An example might be an outbreak of smallpox due to a bioterrorist attack.
Arguments against compulsory immunization
(i) Respect for parental autonomy
Respect for the autonomous choices of other persons is one of the most deep-rooted concepts in moral thinking. It is tempting for proponents of immunization to say that a child cannot make an autonomous decision about immunization and we should over-rule parents who decline to have their children immunized. But how far should we interfere with parental choices about child rearing? In any society, particularly a pluralist or multicultural society, there are many views on what is acceptable in rearing children. In general, parents have to live with their choices for their children and it is usual to respect such parental choices. The only exceptions to this are when the parents’ actions or choices result in serious harm or neglect, i.e. child protection issues.
(ii) Rights-based: rights of the parents
A rights-based approach can also be used to argue against compulsory immunization, because the child's parents also have rights. These rights derive from the fact that they conceived, bore and reared the child and have a significant emotional and financial investment in the child's current and future well-being. This creates an obligation on others to respect parents’ right to bring up their children as they see fit, unless they cause serious harm to the child. To argue that parents should be compelled to immunize their children in the child's ‘best interest’ is to ignore the fact that a child is part of a family. The child of parents who are religiously or philosophically opposed to immunization is quite likely to grow up opposed to immunization. To have been forcibly immunized in childhood will then be viewed by the adult as a societal assault.
(iii) Variable risk-benefit of different vaccines
Even if protection of the community is a compelling communitarian argument for compulsory immunization, it only applies to transmissible infections, and not tetanus. Furthermore, the risk-benefit equation varies from disease to disease and varies over time for a single disease, depending on incidence. To make all routine childhood immunizations compulsory risks ignoring these important intrinsic differences.
(iv) Trust versus State coercion
The state already applies coercion to many of our daily activities. Do we want to live in the sort of society that extends coercion to routine immunization? At present, many industrialized countries achieve high levels of immunization without the need for compulsion. If such high levels can be maintained through encouragement and incentives, this effectively achieves the aims of the moderate communitarian, without the need for legislation. Compulsory immunization would be certain to inflame those who already believe that their Government interferes too much with their freedom. What is more, coercion may alter perception of risk. People who are coerced into an action may be more likely to perceive the action as being risky than if they are persuaded into it. Recent examples, albeit adult rather than child, have been the mandatory immunization of military personnel against anthrax and smallpox, which led to many protests and loss of confidence. Most parents trust the assurances of health care professionals that the benefits of immunizing their child outweigh the risks. Making immunizations compulsory renders trust redundant. If State coercion can be avoided in the area of routine childhood immunization, so much the better.
(v) Practical issues
Even if it was decided that routine childhood immunization should be compulsory, there are potential practical difficulties in enforcement. We often physically restrain a young child to immunize them, but with parental consent. To physically restrain a child and immunize them against their parents’ wish could constitute an assault, which only seems justifiable in a situation of extreme risk, such as post-rabies exposure. The alternative is to introduce sanctions for non-compliance, such as fines or even draconian measures like child care proceedings or imprisonment.
Alternatives to compulsory immunization
Most countries do not have compulsory routine childhood immunization. Instead they employ one or more of the following strategies:
If education of the community and of health care providers about the benefits of immunization achieves levels of vaccine uptake that prevent circulation of infectious diseases, then it is unnecessary to introduce legislation to compel parents to conform.
Inducements may be offered to parents or to providers, such as general practitioners. Inducements to parents usually take the form of linking child care benefit payments and/or maternity benefits to immunization status. Could this be seen as a form of coercion, particularly to poorer families who are far more dependent on such welfare payments? A communitarian might argue that if society provides child and family payments, it is reasonable for society to expect and even demand that children be immunized to help protect the whole community. A comparable situation might be taxes on cigarettes and alcohol. To ban cigarettes or alcohol infringes autonomy and is too coercive. Taxation is less coercive and is proportional (the more you smoke and drink the more you pay). Both taxation of cigarettes and financial penalties for non-immunization follow principles of distributive justice. Smoke if you must, but your taxes will off set the cost to society of smoking-related illnesses. If you choose not to immunize your child, the benefit payments saved will help pay for the cost of infectious diseases.
(iii) School exclusion during outbreaks
In New Zealand and some states of Australia, evidence of children's immunization status must be presented at school entry18. Immunization status rather than immunization is compulsory. Unimmunized children are excluded from school during outbreaks.
(iv) Outbreak legislation
It is possible to enact emergency legislation to compel immunization in the event of an outbreak, such as an influenza pandemic or a bioterrorist smallpox attack. On the other hand, compulsion is scarcely likely to be necessary when the threat of death is very high.
(v) No fault vaccine injury compensation schemes
If the State makes immunization compulsory, then it seems mandatory that the State should compensate the few children who are injured by vaccines. Compensation should be for medical costs, pain and suffering, disability benefits and, if necessary, benefits for loss of earning and death19.
It could be argued that, because parents have their children immunized in good faith, and because no-one is to blame for the rare, severe, unpredictable vaccine injuries that occur, then Governments should introduce no-fault compensation schemes even when immunization is voluntary. Thus no-fault vaccine injury compensation schemes probably ought to be in place regardless of, rather than as an alternative to, compulsory immunization laws. There are at least 13 vaccine injury compensation programmes in the world, and immunization is compulsory in only four of those countries19.
Compulsory immunization will be regarded by many as justifiable in terms of the benefit to the individual child and to the community. But, in order to respect autonomy, State coercion should be kept to a minimum. We believe that, in general, children should not be compulsorily immunized when similar results can be achieved by education and inducements. Australia is in the happy position of having achieved very high rates of routine childhood immunization, over 90%, without the need for compulsion20.
The case for compulsion might be stronger if immunization levels fell, but might not be necessary, because in that case epidemics would occur and the public would quickly recognize the value of immunization.
Whether or not childhood immunization is compulsory, a strong ethical case can be made for introducing a no-fault compensation scheme in Australia, and indeed in other countries.
We would like to express our profound gratitude to Bernadette Tobin of the Plunkett Centre for Ethics in Health Care, St Vincent's Hospital, Sydney for her insightful comments on the manuscript. We also thank Peter McIntyre and Kathy Currow of CHW, David Neil and Justin Oakley of the Department of Bioethics, Monash University, Miles Little and Chris Jordens of the Centre for Values, Ethics and the Law in Medicine, University of Sydney for helpful discussion.