Immunisation and the anti-immunisation movement

One problem in medical practice is deciding which people with unusual symptoms are crazy. I find it helpful to ask these patients whether their illness could have a psychological component.

Patients able to reflect upon and discuss possible psychosomatic influences are usually fairly functional. People who are truly nuts typically deny the merest possibility that they might, indeed, be nuts. The hostility of the denial is often directly proportional to their degree of nuttiness.

Improbable beliefs can, of course, sometimes be socially permissible. For instance, religions can glorify ongoing belief in the face of counter-evidence. Ever greater virtue is demonstrated by maintaining faith in the face of ever greater challenges. In the absence of powerful invisible friends, however, holding a resolute belief despite overwhelming evidence to the contrary is often labelled insane - particularly if gentle challenges to that belief are met aggressively.

At a safe distance via one’s internet connection, aggression and insanity can be interesting to observe. I have therefore discovered that researching beliefs about immunisation can be entertaining. For reasons that might not be immediately obvious, medicines that promote immunity to disease also promote high emotions.

Individuals within both the pro- and anti-immunisation camps demonstrate a degree of intolerance and nutty intransigence to reality. I have, however, reached the conclusion that anti-immunisers do it best. “A special place should be reserved in Hell for the people who want to kill or maim children by preventing them from receiving vaccinations” leaves more room for discussion than, say, “Vaccinations Will KILL You!”

Knowing what one can trust is a core problem of human existence. In my early years of medical practice, an ageing consultant suggested that I should “Trust nobody”. He meant that the conclusions of other practitioners needed testing but he possibly lived by that maxim. He did seem unusually angry, miserable and friendless. Both too much and too little trust can cause people problems.

A few years earlier, as a teenage medical student, I had been struggling to understand the nature of my future trade. The penny finally dropped in the third or fourth year of my studies. The practice of modern medicine is largely about drugs. The use of drugs does, however, depend on trust.

The patients must trust the doctors, the doctors must trust the journals, the journals must trust the researchers, and the researchers must trust the data analysts. Rising life expectancy and falling childhood mortality perhaps has little to do with medicine but do reassuringly suggest that, at worst, these trusts are usually not catastrophically misplaced.

These days, I am able to teach students and trainee doctors that drugs are dangerous so we must prescribe carefully. I might say to trust nobody except I do not want to screw up their personal lives.

I also tell students that research into pharmaceuticals needs careful critical appraisal. Small differences in results can open or close multi-billion dollar markets but the fox is too often in charge of the hen house. Costly major studies can be funded and controlled by the same companies that stand to profit from positive results.

Scepticism is always necessary when research seems to support treatment of huge numbers of people who are not particularly sick - or perhaps not sick at all. It is rational to think carefully before putting ever-larger slabs of the population on, for example, cholesterol-lowering drugs, anti-depressants or hormone replacement therapy.

Pharmaceutical corporations strongly influence journal content. This once led an editor of The Lancet, one of the world’s most important medical journals, to complain that “Journals have devolved into information-laundering operations for the pharmaceutical industry”.

Unfortunately, while unaware of the lead author’s subsequently-revealed conflicts of interest, the same editor published hugely influential but now comprehensively discredited research linking Measles-Mumps-Rubella vaccine to autism. Publicity about this research has been credited with causing a significant reduction in measles immunisation, thousands of excess cases and at least two deaths. Trust nobody, perhaps?

Immunisations are possibly the commonest drugs prescribed to healthy people. We even avoid giving them to the unwell. Given the influence of drug companies over health care, it is not surprising that some people believe that immunisations are drug company scams.

We are currently experiencing a pandemic of swine flu which, in most people, causes symptoms similar to seasonal flu. If the virus becomes more virulent then immunisations could potentially prevent millions of premature deaths. They might also cause a few.

In 1976, fear of a swine flu epidemic in the USA resulted in a now-notorious mass vaccination program that medical authorities acknowledge killed at least two dozen people. This might have been justifiable if the anticipated swine flu epidemic had occurred. It did not. The virus is thought to have only claimed one victim.

On this specific occasion, it was probably safer to risk catching the disease than to risk getting the immunisation. This was, however, an unusual circumstance.

I am no fan of drug companies and I am aware that over the years I have innocently poisoned various patients. Despite this, I think immunisations are the most effective life-prolonging medicaments ever invented.

Smallpox was dreaded for most of human history. In many regions, an epidemic would infect more than half the population and kill up to a third of those afflicted.

People generally do not catch smallpox twice. By some accounts, this allowed tiny doses of smallpox-infected material to be used as immunisations in India and China as early as the 11th century. This probably killed about 1 per cent of recipients. A thousand years ago that represented good odds during an epidemic.

Half a millennium later, similar practices were adopted in the West. This was condemned by some theologians. In 1722, a lengthy sermon titled The Dangerous and Sinful Practice of Inoculation was published. It argued that diseases were punishment for sin and interference with God’s will was diabolical.

The eventual recognition that the milder disease cowpox conferred smallpox immunity allowed development of relatively safe vaccines (vacca is Latin for cow). Edward Jenner usually gets the credit but assorted peasants beat him to it.

For instance, two decades before Jenner’s experiments, a farmer immunised his family with an infected cow’s pus. This worked but the good news was not greeted as Good News. Many locals thought the family would grow horns or turn into cows.

Despite the deadliness of smallpox and the effectiveness of vaccination, there were ongoing campaigns against immunisation. One well-documented epidemic of smallpox in Stockholm in 1873 was attributed to vaccination rates of about 40 per cent due to an anti-immunisation movement. Elsewhere in Sweden the immunisation rate was about 90 per cent. This epidemic faded with mass vaccination and became Sweden’s last.

Smallpox continued to kill millions in the 20th century but vaccination programs gradually and predictably eliminated it region by region. The last death of a naturally-acquired case was in 1977 in Somalia. In 1978, there was a laboratory-acquired UK fatality. Smallpox’s final victim was the professor running the responsible laboratory. He committed suicide.

Another immunisation success is the virtual elimination of polio. Many of my older patients caught the virus during their childhood in the 1940s and 1950s.

While I excised a skin cancer recently, one man with a withered arm asserted his view of anti-immunisers. He thinks they are insane because he personally witnessed a huge fall in polio infections with widespread immunisation. He is still upset that the immunisation became available a few months too late to prevent his disability.

Polio vaccine did in time, however, suffer a cost-benefit dilemma. The commonly-used Sabin oral vaccine uses a weakened, live polio virus which carries in the vicinity of a one in 2.5 million risk of causing polio. This was used in Australia for decades and eventually, perhaps for years, the tiny risk of the immunisation was greater than the even tinier risk of naturally-occurring disease. Australia has now switched to a more expensive injectable vaccine with no associated risk of causing polio.

There have been many other obvious immunisation successes. For instance, early in my medical career, epiglottitis was a much-feared presentation to emergency departments. Just examining a child’s throat could kill them. Epiglottitis suddenly became rare after a vaccine was introduced in the 1990s.

In 2007, I spoke on ABC Radio National about the influence of drug companies over doctors. This included passing comments about possible downsides to the heavy marketing of Gardasil, a human papilloma virus vaccine.

My views were not controversial from a scientific standpoint. Nonetheless, my university’s administrators felt I should apologise to the manufacturers lest it taint a commercial arrangement. This fanned public suspicion that there is something horribly wrong about the cosy relationship between many universities and drug companies.

After my situation became public, the ensuing 15 minutes of fame encouraged a few anti-immunisers to contact me. I could have been the darling of a thousand websites but I told them immunisations had been of great benefit to mankind.

I was also contacted by 60 Minutes. My major concern with Gardasil is its cost effectiveness. The producer’s major concern was side effects, preferably lethal ones. She seemed less interested in quality-adjusted life years or the finite nature of public health budgets.

I said many immunisations carry roughly a one-in-a-million chance of killing the recipient, so a dozen deaths from 20 or 30 million immunisations might be tragic but was not necessarily news. I think they canned the story.

I often tell patients that immunisations probably carry about a one-in-a-million chance of severely injuring or killing them. This means health bureaucrats might kill people by recommending millions of immunisations but I cannot recall any patients refusing a vaccine solely on this basis.

I earlier noted the comment that, “A special place should be reserved in hell for the people who want to kill or maim children by preventing them from receiving vaccinations”. I think this misrepresents the vast majority of anti-immunisers. Most hold sincere concerns that immunisations are not worth the risks. There are good reasons why this view might be stupid - and I have outlined a few - but it need not be malicious.

In fact, a malicious person might prefer to strongly encourage everyone else to accept the inconveniences and tiny risks attendant with immunisation - but not be immunised themselves. If the herd immunity of the population is close to 100 per cent then your individual risk of contracting the infection is close to zero because nobody susceptible can give it to you.

Anti-immunisers, like many people, can struggle with statistics. For instance, some anti-immunisers make much of diseases occurring in immunised people. Yet it is often predictable that the majority of cases of an infection will occur in the immunised. For instance, if 95 per cent of the population receive an immunisation that is 85 per cent effective, then three times as many immunised as unimmunised people will be vulnerable to infection. (After immunisation 15 per cent of the 95 per cent vaccinated are not immune. This is 14.25 per cent of the population, compared with 5 per cent of the population who are unimmunised.)

There is evidence, however, that committed anti-immunisers cannot be swayed by statistics - regardless of whether the statistics are lies, damned lies or self-evident truths. One study suggested opposition to vaccines increased when opponents received information comparing the tiny risks of vaccines to the much greater risks of diseases.

For the most part, I think committed anti-immunisation activists are railing against the success and therefore power of scientific rationalism. This is a straightforward social power struggle between different world views where immunisations happen to be a prominent current battleground. This clash traces back beyond the tribal shaman being irritated about the respect accorded to the inventor of the wheel.

Curiously, the world view that distrusts conventional immunisations often accepts homeopathy. Homeopathy is based on a poorly-validated spiritual view that tiny doses of a toxic substance can be good for your health. Conventional live-virus vaccinations are ironic proof that, at least in one circumstance, homeopathy can work.

Utilitarianism - weighing the costs and benefits of action against the costs and benefits of inaction - is not everybody’s favourite ethic. Nonetheless, a utilitarian analysis underlies many decisions in modern medicine. For example, one hopes the risks of treating a disease are always less than the risks of not treating it; and, of course, that the cost and health risks of immunising are outweighed by the cost and health risks of not immunising.

All vaccinations need individual cost-benefit assessments. It is more important to prevent a dire disease like smallpox than a usually minor disease like chickenpox. It is also more important to prevent common diseases, for instance polio in the 1950s, rather than very uncommon ones, for instance polio now or swine flu in 1976. The current rarity of many vaccine-preventable diseases provides a rational reason to closely assess the risks of vaccines.

In the immunisation debate, as in all disputes, a common human failing must be discarded if one hopes to reach a rational conclusion. Anti-immunisers might argue that humanity almost routinely replaces old facts with new facts and beliefs - but the basic efficacy of immunisation has now resisted refutation for centuries. Beliefs do not change facts but facts should change beliefs.