Model Predicts U.S. Omicron Wave Will Crest by Next Week as U.K. Sees Case Decline

A model from the University of Washington predicts the U.S. Omicron wave will crest by next week as the U.K. sees a decline in cases.

The model projects that the number of daily reported cases in the U.S. will peak at 1.2 million by January 19 and will fall sharply afterward "simply because everybody who could be infected will be infected," said Ali Mokdad, a professor of health metrics sciences at the University of Washington in Seattle.

"It's going to come down as fast as it went up," said Mokdad.

The reason for the decrease is possibly because the Omicron variant is so contagious that it could be running out of people to infect only a month and a half after being initially detected in South Africa.

Britain's COVID case count decreased to around 140,000 a day in the last week after increasing to over 200,000 a day earlier this month, according to government data.

Kevin McConway, a retired professor of applied statistics at Britain's Open University, said that the COVID surge may have peaked in London, despite cases increasing elsewhere, like in southwest England and the West Midlands.

However, experts warn that there is still a lot unknown about how the next phase of the pandemic might proceed. The predicted decrease or plateauing in case numbers in the two countries is not occurring everywhere nor at the same pace. There are also still months and weeks ahead for patients and crowded hospitals even if the wave crests.

Omicron Surge, Crest, U.S., U.K.
Britain’s COVID case count decreased to around 140,000 a day in the last week after increasing to over 200,000 a day earlier this month, according to government data. Above, a man receives a nasal swab during a test for COVID-19 at a testing booth in New York on December 17, 2021. Ed Jones/AFP via Getty Images

"There are still a lot of people who will get infected as we descend the slope on the backside," said Lauren Ancel Meyers, director of the University of Texas COVID-19 Modeling Consortium, which predicts that reported cases will peak within the week.

The figures have raised hopes that the two countries are about to undergo something similar to what happened in South Africa, where in the span of about a month, the wave crested at record highs and then fell significantly.

"We are seeing a definite falling-off of cases in the U.K., but I'd like to see them fall much further before we know if what happened in South Africa will happen here," said Dr. Paul Hunter, a professor of medicine at Britain's University of East Anglia.

Differences between Britain and South Africa, including Britain's older population and the tendency of its people to spend more time indoors in the winter, could mean a bumpier outbreak for the country and other nations like it.

On the other hand, British authorities' decision to adopt minimal restrictions against Omicron could enable the virus to rip through the population and run its course much faster than it might in Western European countries that have imposed tougher COVID-19 controls, such as in France, Spain and Italy.

Shabir Madhi, dean of health sciences at South Africa's University of the Witwatersrand, said European countries that impose lockdowns won't necessarily come through the Omicron wave with fewer infections; the cases may just be spread out over a longer period of time.

On Tuesday, the World Health Organization said there have been 7 million new COVID-19 cases across Europe in the past week, calling it a "tidal wave sweeping across the region." WHO cited modeling from Mokdad's group that predicts half of Europe's population will be infected with Omicron within about eight weeks.

By that time, however, Hunter and others expect the world to be past the Omicron surge.

"There will probably be some ups and downs along the way, but I would hope that by Easter, we will be out of this," Hunter said.

Still, the sheer numbers of people infected could prove overwhelming to fragile health systems, said Dr. Prabhat Jha of the Centre for Global Health Research at St. Michael's Hospital in Toronto.

"The next few weeks are going to be brutal because in absolute numbers, there are so many people being infected that it will spill over into ICUs," Jha said.

Mokdad likewise warned, in the U.S., "It's going to be a tough two or three weeks. We have to make hard decisions to let certain essential workers continue working, knowing they could be infectious."

Omicron could one day be seen as a turning point in the pandemic, said Meyers, at the University of Texas. Immunity gained from all the new infections, along with new drugs and continued vaccination, could render the coronavirus something with which we can more easily coexist.

"At the end of this wave, far more people will have been infected by some variant of COVID," Meyers said. "At some point, we'll be able to draw a line—and Omicron may be that point—where we transition from what is a catastrophic global threat to something that's a much more manageable disease."

That's one plausible future, she said, but there is also the possibility of a new variant—one that is far worse than Omicron—arising.

The Associated Press contributed to this report.