Smallpox re-emergence is real possibility world must prepare for, disease expert warns

Advances in medicine have meant many lives saved over the years, but it also has led to weakened immune systems that would leave people vulnerable to the resurrection of an older, incredibly deadly disease: smallpox.

Professor Raina MacIntyre of the University of New South Wales (UNSW) is sounding the alarm on this fact, saying that while the disease was eradicated nearly 40 years ago, recent events have increased its capability for revival. Further, the CDC had determined that urban spaces such as Sydney and New York City boast weakened immune systems for almost 1 in 5 of their populace, meaning thousands would be especially vulnerable to the disease’s ravages.

“Smallpox was eradicated in 1980 but in 2017, Canadian scientists created a smallpox-like virus in a lab using just mail order DNA”, MacIntyre, a professor of Infectious Disease Epidemiology, said. “Now in 2018, these same scientists published a step by step method to create a poxvirus in a lab, making the threat of smallpox re-emergence even greater.”

In the past, terrorists might have needed to raid government-guarded stockpiles of such viruses to access them. This changes the playing field significantly.

This led MacIntyre to conduct a study based on a mathematical model for identification of smallpox’s potential impact on urban areas. It found that babies through those of 19 years old would face the highest risk of infection, but the highest risk of fatality was faced by those older than 45 years. Even those who had previously received smallpox vaccines are not invulnerable. Vaccination immunity wanes over time, MacIntyre reminds people.

“The rates of immunosuppression were even higher for the age group 60-65 years, because of natural decline of the immune system with age,” MacIntyre said. “We have an aging population, and this must be considered when planning for a bioterrorism attack, and vaccination strategies during an outbreak.”

Professor Tony Kelleher of the Kirby Institute added to this assessment, noting that the increased numbers of people living with HIV and receiving treatments that suppress the immune system adds to the vulnerability of the population.