Axios Vitals

The definition of what it means to be "fully vaccinated" is evolving even as the CDC has remained careful not to officially change it.

Why it matters: CDC officials have been balancing the job of convincing Americans who've already gotten two doses of the importance of boosters with getting many Americans who still need their first doses to get their shots at all.

"What we're really working to do is pivot the language to make sure everyone is up to date with their COVID-19 vaccines as they personally could be, should be based on when they got their last vaccine," CDC director Rochelle Walensky said.

• "If you've recently gotten your second dose but you're not eligible for a booster, you're up-to-date," she said. "If you’re eligible for a booster and you haven't gotten it, you're not up-to-date and you need to get your booster."

Between the lines: This definition has potential ripple effects as cities and businesses around the U.S. mandate shots, many using the CDC's definition of "fully vaccinated" which means a person has completed their primary series of COVID vaccines.

The other side: "When I ask patients 'Are you fully vaccinated and they say 'yes,' they may have gotten that second shot seven or eight months ago. So they are not really protected at the levels we need them to be," Owais Durrani, an emergency medicine physician at UT Health San Antonio, told Yahoo Finance.

What we're watching: When kids under 5 will be able to actually get vaccinated.

• Pfizer's shot likely won't be available until at least the end of March at the earliest, Pfizer board member and former FDA commissioner Scott Gottlieb said on CBS' "Face the Nation" over the weekend.
• Moderna also plans to report its data on vaccines for kids ages 2–5 in March.

The ranks of health care workers are dwindling and stretching what it means to be reaching their "breaking points," particularly at small non-profit hospitals.

The big picture: Even as Omicron cases have begun to wane in some places, many hospitals are still fielding a crush of patients amid record employee callouts.

Yes, but: There's also a growing amount of frustration, burnout and compassion fatigue straining the workforce, the New York Times wrote over the weekend.

• "Frontline medical workers in the U.S. are angry — at the patients who refuse to get vaccinated and at the political leaders who call them 'health care heroes' while opposing mask and vaccine mandates," per the Times.

What they're saying: "The pandemic has laid bare the myriad inefficiencies and frank failures in our health-care system that we had managed to paper over until a real crisis came along," Megan Ranney, academic dean at the Brown University School of Public Health, wrote in the Washington Post.

• "We have served as the safety net for a broken system. But with the serial surges of COVID, we simply can't do it anymore," she wrote.

Beijing Olympics organizers and Chinese authorities have lowered the threshold for producing a negative COVID-19 test for participants arriving to participate in the Winter Games, Axios' Ivana Saric writes.

Catch up quick: Organizers for the Beijing Games had instituted testing standards tougher than those used by many sports leagues in the U.S. and Europe, per the Wall Street Journal.

• The disparity prompted concerns that athletes could test negative in their home countries after recently recovering from COVID-19, but still test positive upon their arrival in China, per the Journal.

What they're saying: "In order to adapt to the reality of the current environment and further support of Games participants, Beijing 2022 and the Chinese authorities, in consultation with medical experts and IOC, refined the countermeasures with the following changes effective 23 January 2022," organizers said in a statement.

Go deeper: "Russian roulette every single day": Olympians desperately evade COVID, the New York Times reports.

• Just because you could find out your genes were hiding important medical information, would you want to? This article explores why some people would rather not. (New York Times)
• A California startup already raised $3 billion and attracted "superstar scientists" in their pursuit of the secret to reversing aging. I'm intrigued... 🧐 (San Francisco Examiner)
• The Wall Street Journal's editorial board offered a rather ... ahem ... hot take on "the real reason" Medicare won't pay for Aduhelm. (Wall Street Journal)