As COVID-19 cases fall and hospitals tiptoe out from yet another surge, the nation is left collectively asking one major question: What comes next?
By now, health experts have made it clear COVID-19 will always be around in some capacity but have stressed uncertainty about the potential scope and severity of future surges.
While difficult to predict what the pandemic's next act could look like, several potential scenarios have emerged in recent months.
Below are four possible paths the pandemic could take in the future, as outlined by physicians, epidemiologists and global health officials:
1. Delta rebound. Delta has seemingly fallen out of the collective pandemic lingo amid omicron's dominance in recent months, though there is still a chance delta — thought to be the deadliest strain thus far — makes a comeback.
In a Jan. 24 op-ed for The Washington Post, Ashish Jha, MD, dean of Brown University's School of Public Health in Providence, R.I., said "It is possible, though unlikely, that the delta variant returns and co-circulates with omicron in different populations, contributing to ongoing infections and hospitalizations."
It's important to note that delta is still dominant in some parts of the world, health experts told The Atlantic, adding that while unlikely, there is a chance it could morph into something that catches up with omicron, allowing the two to tag-team — a dangerous combination given delta's brutality and omicron's transmissibility.
2. COVID-19 may become a seasonal virus. Dr. Jha said this scenario is likely, whether delta makes a comeback or not.
"That means we are likely to see surges in Southern states this summer (as people there spend more time indoors) and in Northern states next fall and winter as the weather turns cold again," he wrote in a Jan. 24 op-ed for The Washington Post.
Emerging evidence suggests COVID-19 may be a seasonal disease, though the research is still preliminary. A July 2021 study from the University of Pittsburgh projected a seasonal COVID-19 pattern in North America with three repeating waves: one starting in New England in the spring, the second starting in the South in the summer, and the third kicking off in the Dakotas in the fall. Based on these findings, researchers predicted the U.S. would see a summer 2021 wave in the South and a fall 2021 wave in North-Central states, which is similar to what happened with the delta and omicron surges. As of November 2021, the study had not been peer reviewed.
3. A new variant emerges. If there's one thing on this list that's near certain, it's that there will be new variants in the future. Global health officials have said they expect future variants to be even more transmissible than omicron.
"Omicron will not be the last variant that you will hear us talking about," Maria Van Kerkhove, PhD, the World Health Organization's technical lead on COVID-19, said Jan. 25. "The next variant of concern will be more fit, and what we mean by that is it will be more transmissible, because it will have to overtake what is currently circulating."
Health officials aren't so much concerned about the emergence of new variants themselves but whether they will cause more or less disease severity. WHO officials have warned against assuming the virus will become milder as it continues to mutate.
"There is no guarantee of that," Dr. Van Kerkhove said. "We hope that is the case, but there is no guarantee of that and we can't bank on it," she added, emphasizing the importance of interventions such as ramping up global vaccination coverage to prevent the emergence of new variants.
Health experts are also concerned white-tailed deer may become a reservoir for the virus to mutate and spread to other animals or back to humans in the form of a new variant.
"This is a top concern right now for the United States," said Casey Barton Behravesh, who directs the CDC's One Health Office, which focuses on connections among human, animal and environmental health. "If deer were to become established as a North American wildlife reservoir — and we do think they're at risk of that — there are real concerns for the health of other wildlife species, livestock, pets and even people," she told The New York Times.
Preliminary findings recently found white-tailed deer on New York's Staten Island infected with omicron, the first time the strain has been detected in wild animals in the U.S. Scientists are still exploring a number of questions regarding the virus's spread among deer, such as how they contract the virus, how the pathogen might mutate inside the host, and whether deer could pass the virus back to humans.
4. The omicron subvariant may spread globally, prolonging the current COVID-19 surge in some parts of the world.
Research shows BA.2 is more transmissible than BA.1, the original omicron strain, though there is no evidence to suggest the subvariant causes more severe illness. The WHO said it expects cases of the omicron subvariant to increase globally due to its growth advantage over BA.1.
"We expect to see BA.2 increasing in detection around the world," Dr. Kerkhove said during a Feb. 8 media briefing.
In late January, Nathan Grubaugh, PhD, an epidemiologist at the Yale University School of Public Health in New Haven, Conn., told The New York Times he was "fairly certain" the subvariant will become dominant in the U.S. but is unclear on "what that would mean for the pandemic."
The BA.2 variant could spur a new surge, but it's more likely that U.S. cases will continue to decrease, according to Dr. Grubaugh. If anything, the variant may simply slow the decline.
Overall, most experts told the Times that BA.2's presence would not significantly alter the course of the pandemic, and so far, data backs this up. COVID-19 cases have been falling nationwide since peaking in mid-January, and modeling from Rochester, Minn.-based Mayo Clinic predicts this trend will continue over the next 14 days.
The weekly number of BA.2 sequences identified in the U.S. has also fallen since mid-January, according to a Feb. 11 U.K. Health Security Agency's report. The U.S. confirmed 191 BA.2 sequences in the week of Jan. 17, which fell to 116 in the week of Jan. 24. In the week of Jan. 31, just four sequences were confirmed, according to supplemental data from the report.