More than 1 in 2 Americans now live in an area where CDC urges indoor masking to curb COVID-19 surges

More than half of Americans now live in communities where the Centers for Disease Control and Prevention urges indoor masking and other measures to curb a surge in COVID-19, according to figures published Thursday by the agency. 

Fifty-five percent of the country's population now live in areas of "high" COVID-19 Community Levels, up from 32% last week, according to the CDC's weekly update. Another 30% are living in counties deemed to be "medium" risk.

At "high" levels, the CDC urges Americans to wear masks and "consider avoiding non-essential indoor activities in public where you could be exposed," among other changes it advises to slow  a wave of infections and hospitalizations. The threshold also triggers additional restrictions at an array of federal facilities, though many local health officials have so far been wary of reimposing mandates.

Earlier this year, the CDC introduced its COVID-19 Community Levels measure as a way to calculate the risk posed by the disease based on a formula that takes into account both reported infections and hospitalizations.

Federal health officials assess that the nationwide tally of COVID-19 cases is likely significantly undercounting the true spread of the disease, given the growing share of Americans turning to rapid at-home tests to diagnose their infections. 

However, COVID-19 hospitalizations have been rising, too. 

For the first time in weeks, the CDC said its national forecast was predicting a nationwide "likely increase" in the pace of new COVID-19 admissions to hospitals. 

Federal data shows most regions are seeing accelerating COVID-19 hospitalizations many times worse than at this time last year. 

Out west, Arizona, California, Hawaii, and Nevada recently saw the pace of new hospitalizations among those 70 years old and over eclipse the worst rates seen during the late summer surge last year. Regions in the Northeast have been experiencing similarly high rates. This age group is the most vulnerable to severe disease and death from COVID-19. 

The ten most populous counties moving from "medium" to "high" this week include: 

• Los Angeles County, California (10,039,107)
• Cook County, Illinois (5,150,233)
• Maricopa County, Arizona (4,485,414)
• San Diego County, California (3,338,330)
• Dallas County, Texas (2,635,516)
• King County, Washington (2,252,782)
• Tarrant County, Texas (2,102,515)
• Suffolk County, New York (1,476,601)
• Fulton County, Georgia (1,063,937)
• Collin County, Texas (1,034,730)

Federal health officials have been urging Americans to take precautions to curb the fast-spreading BA.5 subvariant of Omicron, which is responsible for some two-thirds of cases, according to CDC estimates. 

"It has a growth advantage compared to the earlier Omicron subvariants. It substantially evades neutralizing antibodies induced in people by vaccination and infection. But the vaccine effectiveness against severe disease, fortunately for us, is not reduced substantially or at all compared to other Omicron subvariants," Dr. Anthony Fauci, the president's chief medical adviser, told reporters this week.

Still, CDC scientists and other researchers as a concluded concluded that BA.5's mutations place it the furthest away from the original strain of the virus "than any other variant, including BA.1." 

That fact is part of why the Food and Drug Administration said earlier this month, after a meeting of its outside vaccine advisers, that it would tell vaccine manufacturers to redesign their shots to adapt to the BA.5 variant and its closely related cousin BA.4. 

Those shots could come as soon as October, though the Biden administration has cautioned some Americans will need to wait longer for the updated shots. 

"The entire 105 million doses will not show up on day one, so there will be a rollout period here where I expect some Americans will get it in October if everything sticks to timeline, others will be getting it in November or December," Dr. Ashish Jha, the White House's top COVID-19 official, told reporters. 

However, Jha and Fauci said that federal health authorities are considering allowing already-boosted Americans to renew their protection amid the current wave. 

"FDA is looking at this topic right now and trying to sort out whether they're going to open that up, and then we're going to have a decision on that relatively soon," Jha told "CBS Mornings" on Wednesday. 

So far, only Americans ages 50 and older or those with compromised immune systems can get a second booster shot of COVID-19 vaccine. Of those eligible for the second booster, less than a quarter have gotten the additional dose. 

"In my mind, everyone over 50, if you have not gotten a shot this year, if it's been six months or longer, you got to go out there and get that shot. That to me is a no brainer," Jha said.

CDC Director Dr. Rochelle Walensky also hinted this week that the agency was mulling changes to its COVID-19 guidance amid the growing wave, telling reporters that "as the virus continues to evolve, our response and guidance must evolve with it." 

Among those that could soon see changes is the guidance for nursing homes and other healthcare facilities.

"We are in the process of working on updates that have been pending for a bit, but we are working on updates that will address, in addition to masking, a couple of other areas in the CDC's guidance for nursing homes specifically," the CDC's Kara Jacobs Slifka told attendees to a recent call hosted by the Centers for Medicare & Medicaid Services with nursing home stakeholders. 

Slifka said the agency had changes coming "in the near future" on the topic.

"I think we'll continue to move our recommendations along with where we are trying to go with this pandemic, that this is something that's long-lasting. But we do need to consider where we're at in terms of what the community transmissions and what infections and vaccination status," added Slifka.