- Cases of COVID-19 are surging in several European countries due to the BA.2 subvariant.
- Waning immunity and relaxed public health guidelines could make it easier for the virus to spread in the US.
- Past COVID surges in Europe have been followed by similar waves in the US.
About a dozen European countries are seeing spikes in coronavirus infections due to an Omicron subvariant, and some public health experts in the US are expecting to see a similar wave hit the states in the coming weeks, the Washington Post reported Wednesday.
Cases per million people are on the rise throughout much of Europe, with some of the highest recent infection rates coming from Austria, the Netherlands, Switzerland, and Germany.
Over the weekend, Eric Topol, MD, tweeted graphs from Our World in Data showing the uptick.
—Eric Topol (@EricTopol) March 12, 2022
"The next wave in Europe has begun," he wrote Saturday.
Experts told the Post that the BA.2 subvariant — essentially the original Omicron variant's more contagious cousin — has fueled the recent surge in cases and hospitalizations in Europe.
In a separate tweet, Topol wrote that the rollback of pandemic restrictions, along with a natural waning of the immunity afforded by vaccines, both have enabled the new subvariant to spread widely.
What we know about the Omicron subvariant BA.2
Although the BA.2 subvariant appears to be more than 1.5 times more infectious than the previous iteration of the Omicron variant, according to early data, there's no evidence indicating the new version causes more severe disease than its predecessors.
Some reports have described BA.2 as harder to track compared to BA.1. Scientists tracked the spread of the original Omicron variant by looking for a specific genetic mutation, which BA.2 lacks.
The subvariant will still cause someone to test postive for COVID-19 on a PCR test, but it'll take extra genetic analysis for researchers to connect new cases to the Omicron lineage.
Experts are braced for the same thing to happen in the US
The US Centers for Disease Control and Prevention has been tracking the spread of BA.2 compared to other Omicron subvariants, but the agency has not sounded the alarm yet.
Overall, the number of new COVID cases and hospitalizations in the US has declined in recent weeks, and the proportion of cases attributed to BA.2 is on the rise. As of March 12, the CDC estimated that BA.2 caused almost a quarter of new COVID cases in the US.
However, the subvariant is already more prevalent in certain regions of the country, specifically the Northeast. New York, New Jersey, Puerto Rico and the Virgin Islands are seeing 39% of total cases attributed to BA.2, and New England isn't far behind, Reuters reported.
The US also has a lower overall vaccination rate than most of the European countries currently seeing spikes in cases, according to data from the Johns Hopkins University Coronavirus Research Center. About 66% of the US population is fully vaccinated, while Germany and the UK have vaccination rates of approximately 76% and 74%, respectively.
"Any place you have relatively lower vaccination rates, especially among the elderly, is where you're going to see a bump in hospitalizations and deaths from this," Celine Gounder, an infectious diseases physician and editor at large for public health at Kaiser Health News, told the Post.
Vaccination rates and restrictions will affect the spread
As it stands, most US counties have a low enough level of COVID-19 cases that they can relax mask recommendations, according to the CDC's latest guidelines.
The agency has made an explicit effort to "give people a break" from wearing masks indoors in recent weeks as cases, hospitalizations, and deaths due to COVID have declined.
That break could be short-lived if the US sees a similar outbreak to what's currently happening in Europe, as CDC Director Rochelle Walensky has said she'll reinstate national mask guidelines if COVID levels worsen again.
Some experts told the Washington Post they have already opted to keep their masks despite the CDC's changing guidelines, considering the rise of a new variant on the rise at home and abroad.
"Why wouldn't it come here? Are we vaccinated enough? I don't know," Kimberly Prather, an aerosol transmission expert at the University of California at San Diego, told the Post. "So I'm wearing my mask still … I am the only person indoors and people look at me funny and I don't care."
The protection afforded by vaccines, while still widely effective at preventing hospitalizations and deaths due to COVID-19, is not as strong as it was when people first got vaccinated in late 2020. Vaccine-makers have urged the approval of a fourth shot to enhance immunity for adults 65 and older, and it's possible we'll see an annual COVID booster in the future.