On Friday, the Centers for Disease Control and Prevention held a telebriefing.

Director Rochelle Walensky presided, along with two career scientists. The substance was notable — updated COVID-19 guidance for K-12 schools.

But even more notable was the fact that the briefing was happening at all.

It was the first such briefing in months, despite the ongoing pandemic crisis.

Two days before Christmas, with the Omicron variant driving a near-vertical rise in new coronavirus cases, the director of the Centers for Disease Control and Prevention alerted the White House that she planned to recommend that people infected with the virus isolate for five days instead of 10.

Advisers to the Centers for Disease Control and Prevention endorsed a coronavirus booster-shot-for-all policy Friday, voting to allow all adults to get an extra shot of the Pfizer-BioNTech or Moderna vaccines. In a separate last-minute vote, they also recommended the shots for all people 50 or over.

A Centers for Disease Control and Prevention panel on Friday unanimously approved recommending booster shots of the Pfizer-BioNTech and Moderna vaccines for all adults.

The CDC panel said anyone 18 or above can get a third shot, while recommending that Americans over the age of 50 should get one. A final decision by the agency is expected later Friday.

Earlier in the day, the Food and Drug Administration approved requests by Moderna and Pfizer to get booster shots into the arms of all adults nationwide.

A key outside advisory group to the Centers for Disease Control and Prevention (CDC) has endorsed the use of COVID-19 booster shots for all adults, a one-size-fits-all approach designed to simplify eligibility.

If CDC Director Rochelle Walensky signs off on the broader use, as expected, the extra shots will be available immediately to all adults, as long as they are six months past the final dose of a Pfizer or Moderna vaccine, or two months after a Johnson & Johnson dose. 

The newly installed director of the Centers for Disease Control and Prevention had one big request for agency employees at an all-hands meeting in March: Don’t talk to the press without permission.

Rochelle Walensky’s remarks caught many CDC scientists and officials off guard. Her boss, President Joe Biden, had campaigned on a promise to take control of the pandemic by letting science lead — a pledge that hinged almost entirely on allowing the nation’s top health experts, including those at the CDC, to speak publicly.

Since the early days of her time as Director for the Centers for Disease Control and Prevention, Dr. Rochelle Walensky has made comments and claims over Covid-19 guidance that her own agency, and sometimes the White House, have walked back or toned down.

As COVID-19 cases creep up again across the country, federal officials and epidemiologists say they're worried we could hit another tipping point, leading to a fourth significant surge of infections, hospitalizations and deaths.

"We're skating on a knife's edge right now," said Nicholas Reich, a biostatistician at the University of Massachusetts Amherst.

New Covid-19 cases, hospitalizations and deaths are beginning to rise in the US again, one of the country's top health leaders said Monday.

Vaccinations are proceeding, even accelerating, but COVID-19 cases are rising, and Americans should remain very concerned, President Biden and members of his administration warned on Monday:

"Our work is far from over. The war against COVID-19 is far from won. This is deadly serious," President Biden said.