(NEXSTAR) — Cases of the omicron variant are spreading so rapidly in the United States, the curve of new COVID-19 cases looks more like a straight vertical line.

Over the past week, the country has seen an average of about 580,000 cases per day — with one day spiking up past 1 million new reported cases — shattering records set earlier in the pandemic.

When will things turn around and omicron start to dip?

Dr. George Rutherford, an epidemiologist at the University of California, San Francisco, predicted we’ll see our peak in the second or third week of January before numbers start to fall.

Dr. Davidson Hamer, a professor of global health at Boston University, estimated a similar timeline. “Right now we’re still in the upswing for most parts of the country,” he said. “My prediction would be within the next two to four weeks, we’re going to see it (reach a peak) and start to drop.”

Epidemiologists are looking to South Africa, the first country where the variant took off, for clues on what might happen here.

“They peaked out in about four weeks and then started to drop,” said Rutherford. “They were at about 38% of their apex on Monday, so it was a very steep drop.”

Will our decline be as steep as South Africa’s? “Judging by the past, I would say slowly is the more likely (scenario),” said Hamer.

Rutherford is watching the U.K. and Denmark for more clues on what’s to come. Both European countries were a bit ahead of the U.S. in their omicron surges, and both are still reporting increased new COVID-19 cases, just at a slower clip than a few weeks ago.

The reason for omicron’s meteoric rise is also responsible for its steep decline: it’s so contagious, it blazes through the population.

“It’s so infectious and it has infected so many people, so it has exhausted the ‘susceptibles’ pretty quickly,” said Rutherford. The more people who are fully vaccinated and boosted, the smaller the “risk pool” is this time around, he added.

Nexstar’s Michael Bartiromo contributed to this report.