Public health is often a battleground. Historically, debates about how to fight contagious disease were more clearly focused when the contagious diseases in question were seriously life-threatening. This year's alarm about the menace of the H1N1 virus is proving particularly problematic, for reasons ranging from the anxieties of anti-vaccinationists to the indifference of those who cannot see why they should panic about a relatively insignificant threat.
The practice of vaccination began in Britain in the 1790s when Dr. Edward Jenner observed that inoculation with cowpox virus (variolae vaccinae) created immunity to the smallpox virus, one of the scourges of humanity. For many centuries, smallpox had ravaged populations, killing about 20 per cent of its victims, and leaving many more blind and disfigured. Vaccination was instantly hailed as a great medical breakthrough, was very widely adopted and quickly began to reduce the carnage of smallpox.
From the beginning, however, skeptics attacked vaccination as potentially harmful, oversold, unnecessary and aimed at lining vaccinators' pockets. The idea of ingesting a sometimes toxic foreign substance was not intuitively acceptable to many people. They had to learn to weigh their natural fear of vaccination against the greater threat of smallpox. In the 19th century, vaccinophobia had to be overcome by extensive campaigns of public education, persuasion, hectoring and, as a last resort, compulsion. It was a long uphill struggle, and not without terrible setbacks.
In 1885, public-health officials in Montreal, then Canada's largest city, tried to stop a small outbreak of smallpox by offering extensive public vaccination. There was a tradition of suspicion about vaccination in Quebec, a tendency to take smallpox for granted as one of the many diseases sent by God to punish sinners. When the first vaccines used in Montreal turned out to be contaminated, causing cases of erysipelas, fear of the vaccine became greater than fear of smallpox. With vaccination suspended or resisted, the virus spread like wildfire among unvaccinated French-Canadian children, and within a few months caused more than 3,000 of them to die horribly, unnecessarily. Enlightened - and vaccinated - observers were appalled that fear, ignorance and fatalism had combined to trump common sense and good medical judgment. There had been rioting in Montreal's streets when the Board of Health tried to make vaccination compulsory.
After this disaster, the last major epidemic of smallpox in a major city, serious enforcement of compulsory vaccination, supported by such contagion-control measures as closing of schools and churches, became common resorts in the 20th century's mopping up of smallpox in every advanced country (though the phrase "conscientious objector" was coined in England to describe certain anti-vaccinationists). That campaign ended triumphantly in the 1970s, when smallpox disappeared. The last Canadian case was in 1962, the last case anywhere in the world was in Somalia in 1977.
If smallpox were to appear in any country today, there would be immediate resort to widespread and compulsory vaccination, along with compulsory enforcement of isolation and quarantine. Similarly draconian measures were surely being contemplated by public-health officials in Canada in 2003, when it briefly seemed that the powerful SARS virus had the potential to rage out of control.
THE DEFEAT OF SCOURGES
Louis Pasteur called his procedure to immunize against rabies "vaccination" in homage to Jenner, and the term now is used to cover most immunization processes. Over time, researchers developed vaccines against other horrible scourges - the defeat of polio by the Salk and Sabine vaccines since the 1950s has been particularly notable - and even against diseases that had previously been considered mild rites of childhood, including measles, mumps and chicken pox. In the last few years, vaccines have become increasingly the weapons of choice against the constantly mutating influenza virus. Some influenza strains are more dangerous than others. In 1918 there was no vaccine to protect against a particularly serious form of the virus, and it killed tens of millions. Helpless populations could only try to reduce contagion by wearing masks and staying away from possible contacts.
Even as vaccination has become more widely prescribed, safer and generally accepted, anti-vaccinationism has persisted as a minor but tenacious challenge to the medical consensus. As well, the fear-risk-benefit calculations we have to make in getting vaccinated change slightly with each disease. Few sensible people would not accept vaccination against smallpox, if it became necessary, or against polio. There has been significant resistance to measles vaccine (Quebec is still the centre of Canadian anti-vaccination sentiments), considerable indifference to vaccination against chicken pox, a raging debate about vaccinating girls for human papilloma virus, and fairly tepid compliance with recommendations for annual vaccination against the prevalent strain of influenza.
As the diseases we vaccinate against become less menacing, many citizens who have no hang-ups about vaccination per se just can't be bothered with the minor irritation and inconvenience. On the other hand, many people in modern societies are willing to go to considerable lengths to try to protect themselves against fairly unlikely contingencies. In the age of seat belts and airbags and children's car seats and helmets and life jackets, we no longer accept the levels of risk our parents took for granted.
Thus the stage was set for this year's public-health paradox: that the surprise appearance of an unusually mild strain of influenza is causing a state of immoderate alarm that is hugely disproportionate by past standards. To some extent it's been stirred up by journalists and public-health officials predisposed to attracting attention by trading in worst-case scenarios. More charitably, it has proved extremely difficult to strike a balance in explaining the threats posed by a new strain of virus and the strains that even a small proportion of severe cases might cause for an already over-burdened health-care system. "It's a very serious situation … but there's no need for alarm." we are told. "If you aren't vaccinated you're not at serious risk … but it's socially irresponsible not to get vaccinated." The subtleties get lost in the verbal shuffling.
Even in the old days of great crusades against terrible diseases, public-health officers could not take their authority for granted. In free societies, people make up their own minds, even on medical subjects. Conscientious objection is always an option. And when experts appear to be wrong or even confused in risk-assessment, especially if they're found to have been wrongly calling wolf, they can unintentionally undermine public confidence. Sometimes I think that our public-health experts could benefit from some of the more intelligent advice prescribed by professional media spin doctors.
THE THREE CAMPS
You would not know it from our public discourse, but Canadians, like the people of most prosperous countries, are among the healthiest humans in all of history. We live longer, our bodies are stronger, our physical capacities are greater than those of any peoples who came before us. Modern affluence, modern nutrition and modern medicine - including the vaccines that have been so effective in protecting us from the really dreaded diseases - have done wonderful things for us. No wonder most of us are glad to live at this time in history, rather than in any era of the plague-ridden past.
When it comes to thinking about our health, we seem to divide into three camps. At one extreme are the fearful, those predisposed to see health as infinitely fragile and constantly menaced by terrible threats - killer viruses in the eyes of some, killer vaccines in the view of others. It's the anxious and the obsessive who are the loudest voices in the media, clog clinics and hospitals, fulminate against demonic vaccinators and incompetent doctors, and try to weave suffocating protective cocoons around themselves and their families.
At the other extreme are the indifferent and irresponsible, who take their good health, their apparent immunity to disease and disease-talk for granted, and just tune out. We're all right, Jack. Not our problem. Cough, cough.
Most Canadians probably fall into a middle group. They're sensible people who don't like being sick, care for each other and take reasonable precautions to protect themselves and others. They have a sense of their good fortune in living in the 21st century and a sense of proportion about their priorities. When our health is at risk, we pay attention to our doctors and take our medicines and our vaccines. Then we get on with the important things of life, which centuries of progress and dedicated public health professionals have made it possible for us to enjoy. We go to concerts and movies and schools and churches and Tim's and we shake hands and kiss and hug one another without giving disease a second thought.
Life's too short to be spent thinking about sickness.Michael Bliss is a historian whose books include Plague: When Smallpox Devastated Montreal (HarperCollins).