CDC Data: BA.2, or ‘Stealth’ Omicron, Responsible for Nearly a Quarter of New Coronavirus Cases | Health News

BA.2, or “stealth” omicron, was responsible for more than 23% of coronavirus cases in the U.S. last week, the CDC estimates – up from 13.7% the previous week, a figure that itself was revised upward from about 11%.

Studies show that the subvariant – unofficially known as “stealth” omicron due to a testing response that makes the lineage look like the delta variant, making additional sequencing necessary – is more contagious than the already highly transmissible BA.1.

Research additionally suggests that BA.2 can reinfect people shortly after they recover from the more common lineage of omicron, though the occurrence is “rare” and seen “mostly in young unvaccinated individuals with mild disease not resulting in hospitalization or death.”

Health officials have raised concerns that the relaxation of mitigation measures like mask mandates could give the subvariant an extra advantage as it spreads in the U.S. Under new CDC guidance, more than 98% of Americans don’t need to wear masks indoors.

Meanwhile, a handful of countries are observing a rise in coronavirus cases, some of which after recently lifting restrictions following the omicron variant’s surge this winter. In the U.K., the rise is being attributed by some experts to BA.2, while Germany continues to see high case counts, and France, Switzerland, Italy and the Netherlands appear to also be seeing increases.

In Shanghai, schools returned to virtual learning, neighborhoods were put on lockdown and residents were told not to leave unless absolutely necessary as mainland China faces its worst COVID-19 outbreak since the outset of the pandemic in 2020.

White House press secretary Jen Psaki said the administration is watching the BA.2 variant closely, explaining that it has “circulated in the United States for some time.”

“I would also note that, while BA.2 is a more transmissible version of omicron, the tools we have – including mRNA vaccines, therapeutics and tests – are all effective tools against the virus. And we know because it’s been in the country,” Psaki said, comparing the situation in the U.S. to countries like China, where a zero-tolerance COVID-19 policy has been employed.

While U.S. officials have cited “widespread population immunity” amid the relaxing of mitigation measures in recent weeks, experts are quick to point out that immunity from both vaccination and infection fade, and measures might need to be reimplemented in the future. And there’s always the lingering fear that the longer the virus spreads the greater the possibility of a new and even more deadly variant.

Pfizer CEO Albert Bourla earlier this week touted the need for the extra shot to avoid another coronavirus surge. The drugmaker requested authorization from federal regulators for an additional booster shot of its coronavirus vaccine for seniors on Tuesday.

“Right now, the way that we have seen, it is necessary, a fourth booster,” Bourla said Sunday on “Face the Nation.” “The protection that you are getting from the third, it is good enough – actually quite good for hospitalizations and death. It’s not that good against infections – but it doesn’t last very long.”

But the White House gave a stark warning on Tuesday: The administration won’t be able to keep up its response to the coronavirus pandemic and provide more vaccines, treatments and testing if Congress doesn’t quickly approve a new round of federal relief.