Smallpox has been responsible for up to a billion deaths since it emerged around 10,000 BC, before it was finally eradicated by a worldwide vaccination program. Since 1977 we have been smallpox-free.
The only samples of smallpox left are kept under guard at the Centers for Disease Control and Prevention, the Vector Institute in Russia, and World Health Organization (WHO) laboratories.
However, bad news, in 2017 Canadian researchers were able to make a smallpox-like vaccine in the laboratory, raising concerns that bioterrorists could themselves synthesize a virus and unleash it on an unprepared population.
Several terrorist groups have declared intent to commit biological attacks of this kind, which is especially worrying as most people have not been vaccinated against the disease. Why vaccinate against something that no longer exists?
Researchers at the Kirby Institute have now run a simulation of what we might expect if smallpox was released into the population, and it does not look good for humanity.
The simulation, rather ominously named "Exercise Mataika", looked at a hypothetical attack where smallpox was deliberately released in Fiji, followed by a larger release in an Asian country with a bigger population.
"Using mathematical modelling of smallpox transmission, we simulated a worst-case, large-scale bioterrorist attack," explained Professor Raina MacIntyre, head of the Kirby Institute’s Biosecurity program.
The research, published in Global Biosecurity, took into account clinical, public health, emergency, and societal responses, with participants from government and non-government organizations around the world making realistic, real-time decisions.
So how does it all go down?
The first case goes to a private hospital in Fiji, where the diagnosis is missed due to unfamiliarity with the disease. This is based on a real case of smallpox in Yugoslavia in 1972, where the disease hadn't been seen in 30 years.
Whilst they await autopsy results, more cases start to appear.
Two Weeks Later
Cases have reached at least 200. Fatality estimates are at 40 percent. The health system is overwhelmed, and media reports are causing panic. Test results confirm smallpox and the WHO declares a Public Health Emergency of International Concern.
Interviews with patients confirm the outbreak began at an airport on August 1. Law enforcement investigates.
Next Few Months
The WHO has deployed its stockpile of 2.7 million vaccines, starting with public health responders who then had to wait seven days before being deployed.
Vaccination in Fiji begins on day 40, prioritizing people who have come into close contact with confirmed cases. Airports are closed after bioterrorism is confirmed, and people are trapped on the island. There aren't enough hospital beds.
The strain is confirmed to be engineered, though on the bright side it is clinically responsive to available antiviral drugs and vaccines appear to be highly protective.
The epidemic spreads across the globe in a matter of weeks from patients who flew from Fiji on Day Zero. More people try to escape Fiji illegally, contributing to the spread.
There are 1,000 first-generation cases infected at the airport and 15,000 second-generation cases to deal with when a second attack takes place in Asia, catching the world off guard.
Response isn't well coordinated, and crisis communication is "poor". At its peak, only 50 percent of smallpox cases are isolated, and 50 percent of contacts are tracked and vaccinated, causing "a catastrophic blow-out in the epidemic".
"In the final phase of the epidemic, which becomes a pandemic, the workforce is decimated, leaving critical infrastructure, transport, power, communications and food supplies compromised," the authors write.
"Government assets are generally dispersed, depleted, and not readily available, resulting in severe conflicts regarding prioritization of limited supplies to health, police and border protection. Dissent is quashed using various means and penalties for insubordination are increased in uniformed services. Key modern systems become unreliable, including wireless and data communications, economy and banking (cash supply), replacement parts and manufactured items, processed food, and medications."
Conspiracy theories are rife, and trust in government wanes, leading to further problems as the populace refuses vaccines.
Under this scenario, it takes 10 years to stop the pandemic.
"The final impact of the pandemic is more severe than a single nuclear strike, and societies are left decimated."
So, uh, that's very reassuring.