Evolution of the SARS-CoV-2 (new coronavirus) pandemic is most likely to resemble past influenza pandemics, according to a team of researchers at the Center for Infectious Disease Research and Policy (CIDRAP), which is led by University of Minnesota infectious disease expert Dr. Michael Osterholm.
A release detailing three scenarios that could unfold over the next 18-24 months explains that the coronavirus pandemic's "future course is still highly unpredictable," but the best comparative model is pandemic influenza.
"Since the early 1700s, at least eight global influenza pandemics have occurred, and four of these occurred since 1900—in 1918-19, 1957, 1968, and 2009- 10. We can potentially learn from past influenza pandemics as we attempt to determine a vision for the future of the COVID-19 pandemic."
The release states that recent coronavirus strains, SARS and MERS, were "substantially different" from SARS-CoV-2 and because of that they don't serve as useful examples to predict how this pandemic will evolve.
There are, however, similarities between SARS-CoV-2 and pandemic influenza. The CIDRAP team listed these as those reasons:
- Respiratory spread mainly through large droplets.
- It can spread through smaller aerosols and via asymptomatic transmission.
- It is capable of infecting millions of people and moving rapidly around the globe.
Minnesota health leaders have long discussed the likelihood of the pandemic hitting the state and rest of the world in waves, with the current outbreak considered the first such wave.
According to Osterholm and CIDRAP, seven of the last eight major influenza pandemics had an "early peak that disappeared over the course of a few months" before a "second substantial peak" arrived approximately six months after the first peak.
The three scenarios CIDRAP focused on:
Scenario 1: Peaks and valleys
First wave in spring 2020 (now) followed by a series of smaller waves that last through the summer and consistently over the next year or two, gradually diminishing in 2021.
This scenario could feature outbreaks that vary by location and would depend on what types of mitigation are enforced.
Scenario 2: Fall peak
After the spring 2020 peak, a larger wave arrives in the fall or winter of 2020with one or more additional waves in 2021. The research says this scenario would be similar to what happened with the 1918-19 Spanish Flu.
Influenza pandemics in 1957-58 and 2009-10 followed a similar pattern.
Scenario 3: Slow burn
Cases and deaths continue to occur but it would likely not require continued mitigation but could result in hot spots of outbreak in certain locations. Past influenza pandemics didn't follow this pattern, but the research says this could happen with COVID-19.