About 73 percent of Americans are currently immune from the Omicron coronavirus variant, and that number could rise to 80 percent by mid-March as the highly infectious COVID-19 strain continues to circulate, the University of Washington’s Institute for Health Metrics and Evaluation estimated for The Associated Press. 

About 50 percent of eligible Americans are fully vaccinated and boosted, about 80 million COVID-19 infections have been confirmed, and many other infections were never reported. The IHME modelers took those figures into account and tried to fill in the blanks by looking at health data from Britain, Denmark, South Africa, and other countries, AP reported Thursday. With three-fourths of Americans having some level of protection, “future spikes will likely require much less — if any — dramatic disruption to society.”

“I am optimistic even if we have a surge in summer, cases will go up, but hospitalizations and deaths will not,” IHME’s Ali Mokdad tells AP. But even in the most optimistic estimates, some 80 million Americans are still vulnerable to a dangerous virus,  and “the 26 percent who could still get omicron right now have to be very careful,” Mokdad added. “We’ve reached a much better position for the coming months, but with waning immunity we shouldn’t take it for granted.”

Millions of Americans don’t have immunity because they refuse to get vaccinated, but there are also more than seven million immunocompromised adults in the U.S. who will likely never have strong immunity and tens of million more with at least one medical condition that puts them at greater risk of serious COVID-19 infections, The New York Times reports. “And they have seethed over talk from politicians and public health experts that they perceive as minimizing the value of their lives.”

Transplant recipients, cancer patients, and others with compromised immune systems have been “sequestering at home, keeping their children out of school, and skipping medical care rather than risk exposure to the virus” since March 2020, the Times reports. “As Year 3 of the pandemic approaches, with public support for precautions plummeting and governors of even the most liberal states moving to shed mask mandates, they find themselves coping with exhaustion and grief, rooted in the sense that their neighbors and leaders are willing to accept them as collateral damage in a return to normalcy.”