Originally Published: 10 JAN 22 07:43 ET

Updated: 10 JAN 22 14:37 ET

By Susannah Cullinane, CNN

(CNN) -- The current Covid-19 surge in the US, fueled by the Omicron variant, could peak later this month -- but the next couple of weeks are critical, a health expert says.

Dr. Ashish Jha, dean of the Brown University School of Public Health, warns long-term planning is needed to avoid continued stress on the health care system, as hospitals become full, schools struggle to keep students in class and testing remains difficult to access.

"We're seeing two sets of things happening: A lot of vaccinated people getting infected. We're doing fine. Largely avoiding getting particularly sick, avoiding the hospital; a lot of unvaccinated people and high-risk people who have not gotten boosted and they're really filling up the hospitals, and so our hospital systems are under a lot of stress," Jha told ABC's "This Week."

"Then we have to start thinking about a long-term strategy for how do we manage this virus and not go from surge to surge feeling like we don't have a longer-termed approach," said Jha.

According to data from the US Department of Health and Human Services, about 24% of hospitals are reporting a "critical staffing shortage."

Of the approximately 5,000 hospitals that reported this data to HHS on Saturday, nearly 1,200 -- about 1 in 4 -- said they are currently experiencing a critical staffing shortage, the largest share of the entire pandemic. More than 100 other hospitals said they anticipate a shortage within the next week.

These staff shortages are growing as frontline health care workers are either infected or forced to quarantine due to exposure to Covid-19 just as the demand for treatment skyrockets: More than 138,000 Covid-19 patients were in US hospitals as of Sunday, according to HHS. That's not far from the all-time peak (about 142,200 in mid-January 2021) and an increase from around 45,000 in early November.

"I expect this surge to peak in the next couple of weeks. It'll peak in different places of America at different times, but once we get into February, I really do expect much, much lower case numbers," Jha told ABC.

One of the tools critical to the fight against Covid-19 is testing, which is still hard to find in parts of the US.

As laboratories struggle to keep up with the increased demand for Covid-19 tests triggered by the surging Omicron variant, at least two health care providers have prioritized coronavirus testing for those who exhibiting symptoms of the virus.

Last week, multiple locations of the University of Washington health care system in Washington state started prioritizing testing solely for people "who have symptoms of respiratory illness or who have a known exposure to COVID-19," spokesperson Susan Gregg told CNN. People without symptoms are not being tested, Gregg said, "due to the high volume of Omicron cases that are being processed in our laboratory."

The University of North Carolina Medical Center in Chapel Hill is facing a similar testing crush and is also restricting Covid-19 tests to those exhibiting Covid-19 symptoms, as well as university employees, and those requiring a test prior to a surgery, according to UNC Health director of news Alan M. Wolf.

In Georgia, the Department of Health announced the opening of two Covid-19 mega-testing sites Friday, as cases across the state continue to rise. Both sites, which are located just outside of Atlanta, are appointment only. The state health department said it's also in discussions to identify locations for additional testing sites.

Dr. Jonathan Reiner, professor of medicine and surgery at George Washington University, said testing is a major key to controlling the spread of Covid-19, including in schools, which are struggling to keep kids in classrooms in areas where transmission is high.

"If you want to get kids and teachers back in schools, the way to do that is a multi-pronged approach, including flooding our schools with testing. Testing kids every week, testing teachers every week," and requiring teaches and eligible students to be vaccinated, he told CNN's Jim Acosta on Sunday.

Balancing health and education

Chicago Public Schools, the nation's third-largest school district, is among those struggling to balance health concerns with educational needs.

Classes in the district are canceled again Monday, for the fourth consecutive school day, after city officials and the Chicago Teachers Union failed to reach an agreement over the weekend on how to handle the city's Covid-19 surge.

The union wants a period of remote learning, citing concerns over Covid safety, while the city wants kids in classrooms.

Atlanta schools were set to return to in-person classes Monday after four days of virtual learning.

Lisa Herring, superintendent of Atlanta Public Schools, told CNN twice-weekly mandatory testing for teachers has been extended to students whose parents consent to testing.

"We want, for as much as we can, to keep our children inside of the brick and mortar, but we do need that data to be able to effectively support and ensure safety for everyone," she said.

Of approximately 50,000 students, they had received around 20,000 parental consent forms for testing, Herring said, and will continue to encourage more.

"We have put in place several mitigation strategies that we are clear can help us keep children and staff in place when we're able to identify positivity data ... But to be clear, we also recognize that in order to ensure health and wellness there will be times within schools or classrooms that pivoting to virtual may be necessary," Herring said.

Los Angeles Unified School District, the second-largest school district in the country, is requiring all students and employees to show a negative Covid-19 test result before returning to the classroom on Tuesday.

The baseline test requirement was implemented at the beginning of the school year in August, and the district announced a week ago both the baseline test, along with required weekly testing for employees and students would continue through January, given the current surge.

To help families meet this requirement, the district has been offering PCR testing at many school campuses over the past week. Take-home rapid antigen tests were also distributed, in line with Gov. Gavin Newsom's announcement in late December that every California K-12 student would be provided with one.

On Sunday, LAUSD Board of Education President Kelly Gonez said about 50,000 positive Covid-19 cases had been identified as a result of the required testing, stopping those students and employees from enter school buildings Tuesday.

Dr. Richina Bicette-McCain, medical director at the Baylor College Medicine, told CNN on Sunday that schools were currently a higher-risk setting for Covid-19 because the tools to mitigate its spread were not being adequately employed.

Bicette-McCain said students needed access to testing and high quality masks and said HEPA filters could be used in schools to increase ventilation.

"Schools could potentially be very safe -- we do have the tools to make in-person learning a safe situation. But when children went away for winter break we were seeing maybe about 120 pediatric cases of Covid in a single week, we were seeing overall in the United States about 170,000 cases per day," she said. "Those numbers have increased exponentially. The environment that children are coming back to is not the same environment that they left from."

She said protocols needed to change. "The numbers we're seeing are likely a gross undercounting of the number of positive cases in the community right now."

Surge hitting hospitals

Hospitals continue to struggle with the number of cases.

In New York state, 40 hospitals have been required to stop non-essential, non-urgent elective surgeries for at least two weeks because of low patient bed capacity, the state's health department said in a statement Saturday.

In late November, Gov. Kathy Hochul signed an executive order outlining a plan to address the Covid-19 winter surge. Part of that order requires that statewide hospital capacity is able to meet regional needs "while maintaining the long-term resiliency of the State's healthcare infrastructure," the statement says.

In some hospitals, up to 40% of patients with Covid-19 "are coming in not because they're sick with Covid, but because they're coming in with something else and have had Covid or the Omicron variant detected," Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Sunday on Fox News.

Walensky said the CDC has been screening "everybody who's walking in the door" in many hospitals, and the breakdown of patients admitted with Covid-19 -- as opposed to for Covid-19 -- has differed by variant.

But Walensky also noted that while Omicron appears to be milder at the individual level, a large volume of cases could cause death rates to rise.

Pediatric cases of Covid-19 are also surging with more than 800 children being admitted to hospital with Covid-19 each day and nearly 84,000 have been hospitalized since the start of the pandemic, according to the latest CDC data.

At Children's Hospital Los Angeles, the positivity rate for children tested for Covid-19 has increased from 17.5% in December to 45% to date in January, according to CHLA Medical Director Dr. Michael Smit.

CHLA currently has 41 patients in-house who have tested positive for Covid-19, and roughly one quarter of the children admitted to the facility with Covid-19 require admission to the pediatric ICU, with some requiring intubation, Smit told CNN on Saturday.

Children face a lower risk of Covid-19 hospitalization relative to other age groups, but "children aren't supposed to die," Walensky told Fox News on Sunday.

The "vast majority" of children who are hospitalized with Covid-19 are unvaccinated, and the best way to protect children from Covid-19 is to vaccinate everyone who is eligible, Walensky said.