Myths of immunity

Fears that the combined measles, mumps and rubella (MMR) vaccine may cause autism have led to the demand that the measles, mumps and rubella components should be given separately.

Popular beliefs about the dangers of immunisation to the immune system and the assertion of the principles of consumer sovereignty now risk putting the whole programme of mass childhood immunisation in jeopardy.

It is first important to reiterate what I have argued before on spiked: there is no good evidence that MMR causes either inflammatory bowel disease or autism, or both (see Immune to the evidence and MMR: injection of fear). It is also true, as some critics of the government’s refusal to introduce separate vaccines have pointed out, that it has not been conclusively proven that MMR does not cause autism.

While it is, of course, impossible to prove a negative, the association between MMR and autism meets none of the recognised epidemiological criteria for causality: the association is not strong, or consistent in different studies; it does not show a clear quantitative or temporal relationship; the proposed biological explanation (the ‘leaky bowel’ thesis) is implausible.

The proposal for single vaccines was made in April 1998 by consultant gastroenterologist Dr Andrew Wakefield, following the publication of his now notorious study postulating a link between MMR and autism. Though Wakefield’s paper reported that, in eight of the 12 cases he presented, the child’s parents blamed the onset of their bowel and behavioural symptoms on the MMR, there was no logical link between this and his recommendation of separate vaccines.

Indeed, none of his team of 12 fellow researchers followed him in this proposal (which was not included in the published paper). If you believe, following Wakefield, that it is the measles component of the MMR that causes bowel disease and autism, then why should it not have the same effect when given separately? (It is striking that virtually the only support for Wakefield within the medical profession comes from private GPs who have a commercial interest in exploiting the MMR scare by selling separate vaccines costing a few pounds each to worried parents, at a cost of £50 to £80 a shot.)

Pressed on the incoherence of his case, Wakefield and his supporters fall back on the argument that it is the combined effect of three live vaccines that, in some unspecified way, damages the guts and the brains of infants. They adduce no evidence for this proposition, beyond the intuition that giving three vaccines simultaneously is too much for the infantile immune system.

A much-quoted paper by infectious disease specialist Paul Offit has investigated this issue, comparing today’s immunisation programmes to those of the past (1). The authors point out that though we give infants more vaccines today than in the past, the higher quality of the vaccines means that the number of antigens they receive has declined. For example, the old smallpox vaccine that was used until smallpox was eradicated in the 1970s, contained 200 proteins. Now the 11 vaccines routinely administered in the USA contain fewer than 130 proteins (and more than half of these are in the chickenpox vaccine that has yet to be introduced in Britain).

Offit and his colleagues also calculate that the infant immune system has the theoretical capacity to respond to ‘about 10 000 vaccines at any one time’. Putting this point in another way, they reckon that if all 11 vaccines were given at the same time, ‘then about 0.1 percent of the immune system would be “used up”‘. They insist that ‘young infants have an enormous capacity to respond to multiple vaccines, as well as to the many other challenges present in the environment’.

Wakefield’s hypothesis that the measles virus may cause bowel disease and autism may be described as boldly imaginative or wildly speculative. Though he has failed to substantiate his case, it falls within the framework of legitimate scientific investigation. When he goes on to suggest that a combination of live vaccines may damage the infant immune system, he moves into the realm of lay beliefs about health and illness and the flourishing world of junk science that reflects popular prejudices. Let’s look more closely at these beliefs.

The immune system as metaphor

The concept of the ‘immune system’ is at the centre of contemporary concerns about immunisation, as it is of wider discussions about health. In popular usage, the immune system is understood as the beleagured defence mechanisms of a human body threatened by a wide range of malign forces.

The immune system may be weakened from within, by unhealthy lifestyles and, most insidiously, by the AIDS virus. It is also required to maintain constant vigilance against external threats to the integrity and vitality of the body. The imperilled ‘immune system’ is a metaphor for the prevailing sense of the vulnerability of the human individual in a hostile world.

The term ‘immune system’ is now so familiar that it has the aura of a medical or scientific concept that has been around since the seventeenth century. In fact, the term is scarcely 30 years old. It was first used, by the immunologist Niels Jerne, at the Cold Spring Harbor Symposium on Quantitative Biology in 1967 (2). As Anne Marie Moulin, a historian of immunology explains, the term was introduced as a pragmatic device to hold together two contending factions within the discipline.

On the one hand were those who held that specialised cells (lymphocytes) were the key factor in fighting off infection; on the other, those who emphasised the role of circulating antibodies (immunoglobulins). As Jerne put it, ‘the immune system of an adult person can most simply be described as an ensemble of 10 to the 12 lymphocytes, and 10 to the 10 antibody molecules’.

‘Why was the term immune system accepted so widely and so rapidly?’, asks Moulin. She attributes its success to its capacity to convey different meanings, to its ‘linguistic versatility’. Given that ‘system’ was traditionally understood as ’tissue’, the term implied an anatomical basis for immunity (which was, in fact, very ill-defined). In modern usage, the concept ‘system’ implied structure and invited mathematical modelling. It also referred to a body of knowledge, rooted in the past and carrying great promise for the future, and conferred legitimacy on the emerging discipline of immunology.

For Moulin the immune system ‘was a kind of metaphor’, one that ‘solved the need of communication not only between cells, but between the professionals of immunity’. If, as Moulin notes, ‘in the 1970s, the immune system provided a trendy title for numerous lectures, articles, books, reviews’, in the 1990s, the term moved beyond the world of science and entered a new phase of popularity in the public realm.

The ‘linguistic versatility’ of the term immune system was also the key to its crossover into vernacular notions of science. But the content of the concept also changed in the course of this transition. Though the term was borrowed from the science of immunology, its new meaning was filled out with ideas derived from influential contemporary trends, notably environmentalism, alternative health and New Age mysticism. At a time when these social movements expressed a profound pessimism about the prospects for the planet and a misanthropic outlook on humanity, the concept of an enfeebled immune system reflected the widespread sense of fragile individuality.

In a survey of popular accounts of threats to the immune system, from food additives and pesticides to electromagnetic fields and atmospheric pollution, psychiatrist Simon Wessely notes the centrality of the notion of a threatened immune system:

‘The phrase “overload” is frequently used, to portray the idea of the body, or more particularly its immune system, collapsing under the strain of these environmental insults, and hence paving the way for illness.’ (3)

Wessely comments on the important role of this concept of the immune system in popular understandings of a wave of ‘unexplained somatic syndromes’ – chronic fatigue syndrome (also known as myalgic encephalomyelitis, or ME), food allergies, multiple chemical sensitivity, irritable bowel syndrome, fibromyalgia. He emphasises ‘how scientific concepts, in this setting the role of the immune system, become parodied in the popular literature, which reflects an overriding sense of disquiet about the state of our environment’. (He notes the irony that such beliefs have become so influential at a time when environmental threats to health in Western society have dramatically receded.)

Yet these parodies of the scientific concept of immunity, once the preserve of a bohemian fringe, have won widespread popularity. They are articulated and promoted by practitioners of diverse schools of alternative health, by promoters of austere lifestyles and esoteric diets, and by purveyors of vitamins, anti-oxidants, trace minerals, herbs and homeopathic remedies. They are no longer confined to specialist magazines, but now permeate the mainstream media. They are also increasingly expressed in scientific, or at least pseudo-scientific, jargon, giving anti-scientific prejudices the aura of scientific legitimacy: this is junk science.

High on the list of what many now regard as potential dangers to the immune system are antibiotics and immunisations. Both are regarded as damaging to the operation of natural processes of immunity and as potential causes of illness.

As I have discovered in numerous discussions with patients who hold these beliefs, to inquire as to how antibiotics and immunisations might damage the immune system is to miss the point. These beliefs are not derived from a study of immunology as a science, but arise from a general feeling of vulnerability to a particular sort of danger. This no longer arises from nature as such (in the way that in the past people feared infectious diseases) but from the products of human intervention in nature (antibiotics, vaccines). The linguistic versatility of the concept of the immune system can no longer reconcile people speaking different languages.

The current controversy over MMR reveals the influence of the immune system as metaphor. Indeed, it appears that the origins of the panic lie in the way that elements of the popular parody of the scientific concept of the immune system were adopted by Dr Andrew Wakefield, who was, at the outset at least, a researcher within the medical mainstream. As a result the challenge to medical orthodoxy has appeared to take the form of a division within medicine, rather than an attack from without. The confusions around the concept of the immune system contribute to what often appears like a dialogue of the deaf on MMR. This is also apparent in the discussion over separate vaccines.

The dialectics of choice

The problem of choice arises from the peculiar character of immunisation as something that is inflicted on the individual but can only be effective if pursued in the form of a collective community or nationwide programme against infectious diseases. A recommendation to vaccinate any individual can only be made in the context of an assessment of the prevalence and seriousness of a particular disease, in a particular society at a particular time. From the perspective of the individual, the decisive question is the balance of the risk from having the immunisation (from adverse reactions) and the risk of not having it (and contracting an infectious disease).

For much of the nineteenth century, when smallpox vaccination was compulsory in Britain, most people considered that the balance of advantage lay with vaccination. Even though the incidence of side-effects from the vaccine was high (it occasionally caused fatalities), smallpox was a not uncommon disease causing a high rate of death (and lifelong disfigurement in many survivors). When mass immunisation against diphtheria, tetanus, pertussis and polio was introduced in the course of the twentieth century, early vaccines caused many reactions and a significant number of deaths. But, given the high death rates from these diseases even into the 1940s, there was little opposition to immunisation.

In more recent years, vaccines have become steadily safer, but the diseases they prevent have become increasingly rare. The focus of immunisation policy has widened to take in diseases – like measles, mumps and rubella – that are less serious than the targets of earlier campaigns. When the MMR vaccine was introduced in the USA in the 1970s and in Britain in the 1980s, it was not without its early problems, causing a small number of reactions and some serious complications. However, memories of these diseases were fresh and vaccination against them was popular.

In the 1990s, the immunisation programme ran into was has been called the ‘prevention paradox’: the greater the success at the population level, the less and less health relevance there is at the individual level (4).

Even if the risk of vaccination to the individual is very low, this becomes of increasing concern as the risks of infection become even lower as ever higher population immunisation targets are met and outbreaks become increasingly rare. It becomes a rational choice for parents to opt out of immunising their own children, while enjoying the protection offered to the community as a whole from a high level of herd immunity. The problem, of course, arises when a substantial proportion decide to opt out: at some point, herd immunity is likely to be compromised and outbreaks of nearly forgotten infectious diseases may return.

The response of the government and the medical establishment to the emergence of a minority of dissenters from the national immunisation policy has been to step up the pro-immunisation propaganda and to offer cash incentives to GPs to maintain rates. The public health authorities have been fairly criticised for setting arbitrary targets for herd immunity (why 90 percent?), for playing down the adverse reactions from vaccination, for exaggerating the dangers of a return of particular infectious diseases and the complications associated with them, and for exerting undue moral pressure on dissenters.

Yet even before the current MMR panic, the threat to the immunisation programme was growing. Writing in 1995, sociologists Anne Rogers and David Pilgrim warned that the ascendancy of the programme was ‘precarious and time-limited’ (5). They noted that the programme fitted poorly with increasing expectations of consumer rights, resulting in ‘a conflict of values and interests between state/medical paternalism and citizen consumerism’. The unfolding of this contradiction, compounded by the perception of an immune system in jeopardy and fears of autism, have led to the current debacle.

Choice is an important principle – though in much of Europe and the USA, childhood immunisation is effectively compulsory. The problem is that in the current climate of irrationality around issues of health, it only takes one doctor or scientist to question the safety of any particular vaccine for the entire national programme to be put in question.

In dealing with the MMR scare, the government finds itself in a squeeze of its own making. One the one hand, it has done much to promote popular anxieties about health, contributing to the public sensitivity to the MMR-autism link. On the other, it has elevated the principle of consumer sovereignty, especially in public services, making its resistance to the clamour for separate vaccines appear perverse.

Dr Michael Fitzpatrick is the author of MMR and Autism, Routledge, 2004 (buy this book from Amazon (UK) or Amazon (USA)); and The Tyranny of Health: Doctors and the Regulation of Lifestyle, Routledge, 2000 (buy this book from Amazon UK or Amazon USA). He is also a contributor to Alternative Medicine: Should We Swallow It? Hodder Murray, 2002 (buy this book from Amazon (UK) or Amazon (USA)).

Read on:

spiked-issue: MMR vaccine

ME: the making of a new disease, by Dr Michael Fitzpatrick

(1) ‘Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?’, Paul Offit et al, Pediatrics; 109;124-129, January 2002

(2) See ‘Immunology Old and New: the Beginning and the End’, Anne Marie Moulin, in Pauline Mazumdar, ed, Immunology 1930-1980: Essays on the History of Immunology, 1989, p293-4

(3) ‘Psychological, social and media influences on the experience of somatic symptoms’, 1997

(4) ‘Lay epidemiology and the prevention paradox’, C Davison, et al, Sociology of Health and Illness 1991, 13: 1-19

(5) ‘The risk of resistance: perspectives on the mass childhood immunisation programme’, in Jonathan Gabe, ed, Medicine, Health and Risk: Sociological Approaches, 1995, p 87-88