The trajectory of COVID-19 over the next few months depends on three unknowns: immunity, new variants and our behavior, Sarah Zhang wrote Nov. 18 for The Atlantic.
Despite the growing number of fully vaccinated Americans, experts are unsure of the total percentage of immunity from vaccinations, past infections and combination of the two. The strength of immunity also varies from person to person.
"This uncertainty matters because even a small percentage difference in overall immunity translates to a large number of susceptible people," Ms. Zhang wrote. "For example, an additional 5 percent of Americans without immunity is 16.5 million people, and 16.5 million additional infections could mean hundreds of thousands more hospitalizations."
Another unknown factor that could impact the next phase of the pandemic is the potential for emergence of new variants, despite a "slowed evolution" of the virus.
"We should expect the coronavirus to keep changing," Ms. Zhang wrote.
Lastly, predicting what people will do over the course of the next few months leads to another uncertainty.
"COVID will eventually begin to fade as a disruptive force in our lives as it becomes endemic," Ms. Zhang concluded. "We’re not quite there yet, but our second pandemic winter will bring us one step closer."