The Delta variant seems to have knocked the U.S. off its path of ending the COVID pandemic. As a result of this fast-spreading variant, virus cases are spiking, ICUs are filling up, and officials are considering bringing back mask mandates. According to the Centers for Disease Control and Prevention (CDC), COVID cases have increased by nearly 50 percent in the last week—and more than 80 percent of these new cases are caused by infections with the Delta variant, which is currently the predominant variant in the country. Now, researchers have predicted just how long the Delta variant COVID surge will last.
The COVID-19 Scenario Modeling Hub, a group of researchers working with the CDC to help track the course of pandemic, released new projections on July 21, detailing the course of the spike in coronavirus cases. The researchers created four possible scenarios for its projections, changing based on what percent of the U.S. population gets vaccinated and how quickly the Delta variant spreads.
According to the hub's data, the current COVID surge fueled by the Delta variant will likely continue throughout the summer and fall, peaking in mid-October. At the peak, there will be around 60,000 new cases and 850 deaths each day, Justin Lessler, an epidemiologist from the University of North Carolina who helps run the data hub, told NPR.
"By the time you get to October, these resurgent epidemics have burned through a lot of the people who are susceptible," Lessler explained.
He added that, at that point, "herd immunity starts kicking in a little more aggressively and we start to see things going down again." By Jan. 2022, the data hub projects that the number of deaths will come back down around the current level of about 300 each day.
Lessler told NPR that this is the worst-case scenario but also the most likely, as of right now. In this scenario, the U.S. reaches only about a 70 percent vaccination rate among those eligible, while the Delta variant becomes 60 percent more transmissible.
"What's going on in the country with the virus is matching our most pessimistic scenarios," Lessler explained. "We might be seeing synergistic effects of people becoming less cautious in addition to the impacts of the Delta variant … I think it's a big call for caution."
But there is a chance that the projections change depending on a number of factors, including whether vaccination rates pick back up or COVID restrictions are put back into place, according to Lessler.
"Changes in behavior that we didn't predict and big shifts in vaccination could very much change these results," he said. "I think states should maybe be rethinking the speed at which they're removing mask mandates or social distancing … That is something that—if you want to keep cases under control—certainly would have an impact."