Nearly three-quarters of Americans have some Covid immunity, experts say

Almost three-quarters of Americans are now estimated to have some level of immunity to the Omicron Covid variant that created havoc after it emerged late last year just as people hoped the pandemic was finally waning.

About half of eligible Americans have received booster shots, there have been nearly 80m confirmed infections overall and many more infections have never been reported.

One influential model uses those factors and others to estimate that 73% of Americans are, for now, enjoying protection from Omicron, the dominant variant, and that could rise to 80% by mid-March, experts say.

This will prevent or shorten new illnesses in protected people and reduce the amount of virus circulating overall, probably tamping down new waves. Hospitals will get a break from overwhelmed ICUs, experts agree.

With varying degrees of relief and caution, many Americans are starting to return to their pre-pandemic lifestyles.

Sarah Rixen, 41, of Bismarck, North Dakota, started singing again with a civic chorus after taking a year off. Now, with Omicron winding down, she said she feels more confident than at any time since the crisis began.

As mask mandates ease, workers return to offices and flights fill up, experts are trying to understand whether this return to normal can last, or if another setback is looming.