Over the past year, seemingly endless conspiracy theories
and misinformation campaigns
have gained traction online amid rising Covid-19 infection rates
Looking at the history of these movements can help us understand why they can be so effective at capturing a popular following.
As a historian of medicine, it has become clear from researching the history of vaccines that those who promote anti-vaccination consistently use a standard set of strategies. Although it can be hard to see patterns of argument in the modern context, looking back at a historical instance of epidemic and misinformation provides a useful case study for revealing today's recurring anti-vaccination strategies.
One popular pamphlet
published in 1885 during the smallpox epidemic in Montreal is a great example. Over a century later, we have the benefit of living in a world that has eradicated smallpox using a vaccine
. Yet in the past, smallpox vaccination was hotly contested, despite the evidence in favor of its effectiveness.
Published by a leading anti-vaccinationist, Dr. Alexander M. Ross, this pamphlet was widely circulated during the smallpox epidemic of 1885 in Montréal, as public health officials were seeking to increase vaccination coverage.
Ross seized on the opportunity of increased health measures to gain authority, notoriety and personal fame. He painted himself the hero of his own story, the "only doctor; who had dared to doubt the fetish" of vaccination. Despite this, it was discovered that he had been recently vaccinated during the epidemic
, a fact that was gleefully reported by the major newspapers at the time.
His pamphlet serves as a prime illustration of the strategies used by anti-vaccinationists — both then and now. These arguments are not new and have changed little over time. Learning to recognize their repackaging in modern form can help with effectively combating their power.
Minimize the threat of a disease
Ross and his anti-vaccination associates were quick to dismiss the threat of smallpox. Despite mortality rates of between 30% and 40%
, and the extreme contagiousness of the disease, it was common for anti-vaccinationists to claim that smallpox was only a minor threat to a population.
Ross decried the "senseless panic" caused by health officials and physicians over the epidemic, claiming that smallpox was not, in fact, epidemic, and that the city had "very few cases." Official numbers for the epidemic would eventually rise to 9,600 reported cases with 3,234 deaths — nearly 2% of Montreal's population at the time. An additional 10,000 cases were recorded in the province of Quebec, but historians believe the actual numbers were likely much higher. These numbers and the story of this epidemic have been narrated by historian Michael Bliss in his non-fiction account, "Plague: A Story of Smallpox in Montreal
The minimization of threat is a common tactic in contemporary debates as well. Many who promote the anti-vaccination agenda claim vaccines to be more dangerous than the disease
Claim vaccine causes illness, is ineffective or both
Although modern arguments have focused on the false claim that vaccines cause
autism, historic arguments were much more varied in their allegations of infections from the smallpox vaccine. The anti-vaccinationists of the past claimed that vaccination caused a full spectrum of diseases, from smallpox itself to syphilis, typhoid, tuberculosis, cholera and "blood-poisoning."
These claims were not always groundless, but their risks were consistently exaggerated. Cases had been known to occur of secondary disease transmission due to poor practice
. Some physicians used arm-to-arm vaccination — meaning they would use the same instrument to vaccinate a whole line of people — or used vaccine prepared from a human source rather than a bovine source. The lack of sterile cleaning between operations or the use of vaccine prepared from an infected person could lead to rare cases of secondary disease transmissions.
The discovery of such transmissions (years earlier) sparked some of the first regulations around vaccine preparation and administration, and generated a keen concern within the medical community about vaccine safety — a concern which has continued to be a mainstay of vaccine production to this day