The United States should prepare for another 18 to 24 months of “significant COVID-19 activity” — which likely won’t end until about 60 to 70 percent of the population has been infected, recover and develop herd immunity, experts reveal in a new report.
The report, released Thursday by the Center for Infectious Disease Research and Policy at the University of Minnesota, warned Americans of a worst-case scenario that would involve a larger wave of COVID-19 infections coming in the fall and winter, and one or more smaller waves in 2021.
Even under the best-case scenario — a “slow burn” of ongoing transmission and case occurrence, without a clear wave pattern — COVID-19 deaths will continue to occur, the researchers say.
Another possible scenario involves the current wave of the virus being followed by a series of repetitive smaller waves throughout the summer, and then consistently over a one- to two-year period, gradually diminishing sometime in 2021.
“This thing’s not going to stop until it infects 60 to 70 percent of people,” CIDRAP director Mike Osterholm told CNN. “The idea that this is going to be done soon defies microbiology.”
Osterholm, who has been writing about the risk of pandemics for 20 years and has advised several presidents, wrote the report with several other experts: Harvard School of Public Health epidemiologist Marc Lipsitch; Dr. Kristine Moore, a former Centers for Disease Control and Prevention epidemiologist-turned CIDRAP medical director; and historian John Barry, author of the 2004 book “The Great Influenza” about the 1918 flu pandemic.
Because the pandemic is new, no one has any immunity — so it will likely endure “for 18 to 24 months, as herd immunity gradually develops in the human population,” the researchers wrote.
A conductor wears a mask while waiting for passengers to load into the New York City Subway.REUTERS/Lucas Jackson
The researchers used models presented by other research groups, historical data on past pandemics and published reports about the medical details of the illness to create their projections.
“I have said for a long time that when you are trying to understand how infectious disease is going to unfold, you should rely on history as well as models,” Lipsitch told CNN.
The experts also stressed that “COVID-19 appears to spread more easily than flu,” due to a longer incubation period, more asymptomatic spread and a higher R0, which refers to the average number of other people infected by each patient.
“A higher R0 means more people will need to get infected and become immune before the pandemic can end,” they wrote. “Based on the most recent flu pandemics, this outbreak will likely last 18 to 24 months.”
The release of a vaccine could also affect the course of the pandemic, though one will likely not be available until at least sometime next year, the researchers wrote.
“And we don’t know what kinds of challenges could arise during vaccine development that could delay the timeline,” they added.
The experts say it’s “hard to even understand the rationale” as some states are beginning to lift their restrictions.
“I think it’s an experiment,” Lipsitch told CNN. “It’s an experiment that likely will cost lives, especially in places that do it without careful controls to try to figure out when to try to slow things down again.”