Coercion, compulsion and immunisation

The former head of the British Medical Association, Sir Sandy Macara, has called for the Measles Mumps and Rubella immunisation (MMR) to be a compulsory requirement prior to school entry. The UK has seen a surge in cases of measles over the last couple of years because of a fall in the immunisation rate. Many parents have chosen not to immunise their children as a result of the supposed (and now completely discredited) link between MMR and autism. Immunisation rates have fallen to 70% in some parts of the country. Is compulsory immunisation the answer, and if so, what degree of compulsion should we adopt?

Measles is a serious and potentially deadly infection. 500 children per day die from measles worldwide. Immunisation against measles is extremely effective – it has been estimated that the WHO immunisation strategy prevented 500,000 deaths over the ten-year period from 1995 to 2005. Although in developed countries it often causes fairly mild illness, measles still leads to complications such as ear infections, pneumonia and encephalitis. Measles killed hundreds of children per year in the UK prior to the development of a vaccine in 1963. In 1987, at the time of the introduction of the triple MMR, there were approximately 86000 cases of measles, but by the 1990s the rates had falled to less than 100 per year.

The standard UK approach to immunisation has been ‘persuasion’. Parents are actively encouraged to immunise though coordinated education and information campaigns, coupled with programs of individual reminders and provision immunisation in the local community. Immunisation is a simple effective and safe preventive health measure, so it is entirely appropriate to encourage individuals to take steps to safeguard their own health and that of their children. But immunisation is not simply a matter for individuals. It may be legitimate for individuals to take certain risks with their own health, but in failing to be immunised they risk serious harm to others. For example unimmunised children who contract measles spread infection to infants who are too young to be immunised, or children who develop rubella (German measles) may spread infection to pregnant women causing serious abnormalities in the fetus. Furthermore, for most diseases immunisation is most effective if received in childhood. It is not a question of competent adults autonomously choosing to take on certain risks for their own health. It is often a question of adults imposing a risk on their children. In doing so they may be acting contrary to the best interests of their child.

There is a particular issue for many contagious diseases – like measles, that a certain critical level of immunisation uptake is required to really benefit the community. This is the concept of herd immunity. When a high proportion of the community is immune – as was the case in the UK in the 1990s, it is difficult for the infection to spread. Even if a few people develop infection outbreaks can’t take hold because there is noone to spread it to. It is even possible for the infection to be eradicated from the community because there is no reservoir of infection. But when the proportion falls below this level infections are able to spread again. There were 1300 cases of measles in England and Wales last year compared to less than 60 a decade ago. The herd immunity threshold for measles is thought to be about 90-95%. In other words, if we can make sure that 95% of the community have been immunised we can substantially reduce the number of infections, and the number of people developing complications of measles.

Persuasion has previously been enough to achieve high levels of immunisation in the UK. It would be good if we could achieve these high levels again just through public education and information campaigns. But currently immunisation levels remain disappointingly low. While it has proven extremely easy to scare people about immunisation it is difficult to ‘unscare’ them. That is the reason for Macara’s suggestion that we consider compulsory immunisation.

‘Compulsory immunisation’ might conjure images of children being removed from their parents, or police and doctors invading the homes of immunisation-objectors. But there are degrees of compulsion. Although Australia is sometimes cited as an example of compulsory immunisation, in reality before their child is admitted to school parents need to provide a certificate that he or she has been immunised, that they have a medical contraindication, or that they have been explained the benefits and risks of immunisation by a doctor and have signed an ‘objection’ form. We might describe this as a form of immunisation coercion rather than compulsion. A more stringent form of compulsion is adopted in some American states where parents are denied access to the public school system if their child is unimmunised. Even here there are usually clauses allowing exemptions for religious reasons. A full form of compulsion was in place in a number of countries for smallpox vaccination. In 1905 the US supreme court rejected a claim that such compulsion breached an individual’s constitutional rights. (The penalty for failing to be immunised in 1905 was US$5)

A pragmatic approach to immunisation policy could work sequentially through alternatives. A first step would be to attempt persuasion – as in the current system. If it is not possible to achieve high rates of immunisation simply through persuasion (and we may have reason to doubt this) there is a strong case for a system of immunisation coercion – similar to that provided in Australia. It is difficult to see why there should be any ethical objections to such a system since no parent or individual with a strong objection to immunisation would be forcibly immunised, nor would they be denied access to education. If this were unsuccessful there would potentially be a public health case for more stringent forms of compulsion.

Compulsory immunisation might conflict with the emphasis placed on individual liberty in many countries. But, especially If overall levels of immunisation are low, there is also a child welfare argument for immunisation. Regardless of the benefits of immunisation for others in the community parents may be harming their child by refusing or neglecting to immunise them. Whether the state is justified in intervening in parental choice depends upon how we weigh up the harm to the child compared with the harm of interfering with parental decisions.

Call to make MMR jab compulsory BBC 2/6/09

Why the NHS is facing measles fight BBC 190509

Vaccine refusal, mandatory immunization, and the risks of vaccine-preventable diseases Omer et al New England Journal of Medicine May 2009

Anatomy of a Scare Newsweek March 2009

WHO calls for scaling up of measles vaccination. Children in affluent European countries have a higher risk of infection WHO Regional Office for Europe 26/2/09

Has the 2005 measles mortality reduction goal been achieved? A natural history modelling study. Wolfson et al Lancet 2007

Official warning: Measles 'endemic' in Britain Independent 21/6/08

Compulsory vaccination and conscientious or philosophical exemptions: past, present, and future Salmon Lancet 2006