(CNN) As the number of Covid-19 hospitalizations surpasses those during the Delta variant surge over the summer and fall, more states are enacting emergency protocols to deal with growing staff shortages at hospitals.
The greater transmissibility of the Omicron variant -- which in just one month has led to millions of new cases -- has left frontline workers at a higher risk of exposure, needing to quarantine and recover after positive tests. And health officials are working to plug any gaps in coverage.
In the last week, states such as Ohio, Maryland, Delaware and Georgia have mobilized National Guard members to assist with patient care.
"We still face a very serious situation with Covid-19 in Delaware, especially in our hospital facilities," Gov. John Carney said Monday as about 100 members of the National Guard are training to become certified nursing assistants.
At the MetroHealth Medical Center in Cleveland, officials told CNN that not only is the hospital filled with people needing treatment, but roughly 400 employees are out with Covid-19.
Ohio Air National Guard Cpt. Lanette Looney, who is overseeing the mission at the hospital where 28 Guard members are helping with medical and non-medical tasks, noted they have faced Covid-19 infections as well.
"Within two days of being here, we had four Guard members that were symptomatic with sore throats, headaches, body aches, fever, nasal congestion, and they all tested positive for Covid," she told CNN's Gary Tuchman.
Teams of military medical personnel are working with the Federal Emergency Management Agency to aid with health care staffing in multiple states, including Arizona, Colorado, Indiana, Michigan, Minnesota, New Mexico, Pennsylvania and Wisconsin, US Army North said in a statement Tuesday.
A 15-person team from the Air Force is due to support a hospital in Manchester, New Hampshire, and another 20-person team from the Navy will assist a medical center in Buffalo, New York, the statement said.
More than half of New York state's Covid-19 hospitalizations are currently in New York City, where about 75-80% of hospital beds are full, officials said Wednesday. City Health Commissioner Dr. Dave Chokshi said that while he expects the city's hospitalizations to rise in the coming days, the local hospitalization rate is still well below the spring 2020 peak. Hospitals in the city, he said, are strained because of staffing shortages.
As health care workers are falling ill, hospitalizations nationwide continue to rise. More than one in five hospitals that have an intensive care unit -- more than 700 hospitals -- reported that at least 95% of ICU beds were occupied during the last week of December, according to data from the US Department of Health and Human Services.
In California, where health officials announced Wednesday the state's indoor mask mandate will remain in effect until at least mid-February, Health and Human Services Secretary Dr. Mark Ghaly said it would be the "impact of COVID on our hospital system and its collective ability to serve Californians" that will help determine when the mandate will be lifted.
Meanwhile, the US Centers for Disease Control and Prevention on Wednesday updated its recommendations for the Pfizer/BioNTech Covid-19 vaccine booster to include children as young as 12, at least five months after they finish the primary vaccine series.
Advisers to the agency voted earlier on Wednesday in favor of the expanded use of boosters for children in that age group, as infections nationwide accumulate at a rapid pace.
"It is critical that we protect our children and teens from COVID-19 infection and the complications of severe disease," CDC Director Dr. Rochelle Walensky said in a news release, announcing she endorsed the advisory group's vote.
The US Food and Drug Administration expanded its emergency use authorization for Pfizer's vaccine boosters to children ages 12 to 15 on Monday.
The CDC also updated guidance this week on isolation times.
Recent guidelines from the agency suggested an isolation period of five days after the onset of suspected symptoms or the date of a positive test, and one should wear a mask around others or in public for an additional five days if they are not showing symptoms. If an individual still has symptoms such as fever after five days, they should continue to quarantine until they are fever-free for at least 24 hours.
Yet for those able to get their hands on a rapid test, the CDC updated its guidance Tuesday on the isolation period. If a person has access to a test and is fever-free, the best approach is to use a rapid test toward the end of the five-day isolation period, it said.
The recommendations do not advise a test for isolated people, but they offer guidance on how those people should respond to a test result if they choose to take one. If it's positive, people are advised to continue their isolation until 10 days after their symptoms started. If the test is negative, people can end the isolation but are advised to wear a mask around others until day 10.
The CDC, which received criticism for cutting in half the recommended timeframe for isolation last month, says the changes aim to "focus on the period when a person is most infectious. ... These updated recommendations also facilitate individual social and well-being needs, return to work, and maintenance of critical infrastructure."
In the midst of the surge, some school districts have chosen to return to remote learning for the time being. Yet, this has created friction on numerous fronts.
On Tuesday night, the Chicago Teachers Union voted to teach virtually rather than in the classroom, triggering the cancellation of classes Wednesday.
Underpinning the difficult conversation over whether it's safe for children to return to in-person learning has been data showing a rise in infections.
In what it described as an "alarming increase," the American Academy of Pediatrics said new Covid-19 cases in children increased nearly 64% over the prior week, according to data published Monday.
And an average of 672 children were admitted to hospitals every day with Covid-19 during the week ending Sunday, the highest such number of the pandemic, according to CDC data.
To help stem the tide, health experts urge continued mitigating practices such as mask-wearing, as well as for those unvaccinated and eligible to receive doses to do so before they get infected, protecting themselves and those around from severe illness.
"Being in the hospital is no picnic. And the folks in the hospital are overwhelmingly unvaccinated persons," Dr. William Schaffner, a professor at Vanderbilt University Medical Center, told CNN's Erin Burnett on Tuesday.
"The vaccine and the boosters give you mild infections and keep you out of the hospital. And vaccines are actually working. It's the unvaccinated folks that I am concerned about. Adults and children, together."