, even as states and cities continue to lift restrictions amid low case numbers.
Infectious disease experts are watching BA.2, the Omicron subvariant that appears to be more transmissible than the original strain. BA.2 is fueling outbreaks across Europe and is growing in dominance across the United States.
“It’s picking up steam. It’s across at least 12 countries … from Finland to Greece,” Eric Topol, MD, director of the Scripps Research Translational Institute, told The Washington Post.
He has been following the surge and has posted recent charts of the outbreak on Twitter. Hospitalizations appear to be increasing in some places as well, he noted, despite the higher vaccination rates of many Western European countries.
“There’s no question there’s a significant wave there,” Dr. Topol said.
Germany recorded more than 260,000 new cases on March 15, according to the data tracker from the New York Times, but coronavirus restrictions are still being lifted this week. The U.K. is reporting more than 75,000 daily cases, and the Netherlands is reporting more than 60,000 daily cases, which are considered major numbers, compared to their population sizes. Meanwhile, France, Italy, and Switzerland are also reporting large increases in infections.
During the past 2 years, widespread outbreaks in Europe have been followed by similar surges in the U.S. weeks later. Most experts interviewed by the Post predicted that it’s likely to happen again.
In the United States, the BA.2 subvariant accounted for 23% of new COVID-19 cases for the week ending March 12, according to the latest estimate from the Centers for Disease Control and Prevention, while the original Omicron strain made up about 66% of cases. The BA.2 percentage is up from 13.7% of new cases for the week ending March 5, 7.1% the previous week, and 4.1% the week before that. In parts of the Northeast and New England, BA.2 makes up more than 38% of new cases.
At the same time, the 7 -day average of COVID-19 cases continues to drop in the United States, with about 31,000 daily cases currently, the New York Times data tracker shows. About 25,000 COVID-19 patients are hospitalized across the country, which has fallen 44% in the past 2 weeks, and about 1,200 deaths are being reported daily.
Several variables could affect the course of a future surge, the Post reported. Vaccination rates, coronavirus safety protocols, and access to antiviral medications could dictate how another wave unfolds across the country.
About 82% of the eligible U.S. population has received at least one vaccine dose, and 69% is fully vaccinated, according to the latest CDC data. About half of those who are eligible for booster doses have received one. In Germany, nearly 76% of people are fully vaccinated, the newspaper reported, and in the United Kingdom, about 74% are fully vaccinated.
Health experts are also considering how natural immunity from a previous infection could affect a BA.2 surge. Millions of Americans were infected with the original Omicron strain, BA.1, which could provide protection. That said, researchers aren’t quite sure whether BA.1 infection protects against BA.2.
“It’s like a weather alert. Right now, the skies are sunny and bright, and we hope they stay that way,” Michael Osterholm, PhD, director of the University of Minnesota’s Center for Infectious Disease Research and Policy, told CNN.
“But we could have some bad weather by evening,” he said. “We just don’t know.”
A version of this article first appeared on WebMD.com.