(CNN) -- Hospitals around the United States are racing to keep up with surges of Covid-19 patients at numbers they have not seen at any other time in the pandemic.
At least 123,639 people nationwide were in the hospital with coronavirus on Saturday, marking 32 consecutive days that the number of hospitalizations has exceeded 100,000, according to the Covid Tracking Project.
Cases have skyrocketed after the Thanksgiving holiday, and impacts from Christmas and New Year's celebrations are still unfolding. As of Saturday, more than 20.4 million people have been infected with the virus in the US and at least 350,186 people have died, according to data from Johns Hopkins University. And health experts worry what will happen to those numbers if infections continue to spread.
"This is about total collapse of the health care system if we have another spike," said Dr. Brad Spellberg, chief medical officer at the Los Angeles County-University of Southern California Medical Center. "And we, in the hospital, cannot stop that. We can only react to it. It is the public that has the power to put a stop to the spread of this virus by obeying the public health guidance that have been put out."
In California, emergency room officials said hospitals are treating an unprecedented number of coronavirus patients.
Design and construction experts from the US Army Corps of Engineers have been deployed to the Los Angeles area to "evaluate and where necessary upgrade oxygen delivery systems" at about a half dozen hospitals.
One area hospital converted administrative offices and break rooms into treatment areas for their coronavirus patients, said Col. Julie Balten, commander of the Los Angeles District for the Corps of Engineers.
4 million vaccines administered
Though the distribution of coronavirus vaccines is currently limited to healthcare workers and long term care patients, officials hope the number of cases and hospitalizations will eventually be reduced by the vaccinations.
As of Saturday morning, more than 4.2 million doses have been administered in the US, according to the Centers for Disease Control and Prevention.
Those include doses of both the Moderna and Pfizer/BioNTech vaccines. In total, more than 13 million doses have been distributed, the CDC Covid Data Tracker said.
Despite some delays, the allocation and distribution of the vaccines is working well, said Claire Hannan, executive director of the Association of Immunization Managers.
"We do have a little bit of a lag in the doses administered, so that's coming through a few days after they're delivered. I don't see it as a major system failure," she said. "We just aren't seeing the vaccine going into arms as quickly. But the infrastructure we've set up I think is working."
So far, the vaccines approved in the US require two doses based a few weeks apart -- and the US will keep doing it that way, rather than follow the UK's decision to potentially delay second doses, Dr. Anthony Fauci told CNN on Friday.
The UK adopted that strategy in order to give as many people as possible the first dose as quickly as possible, saying that it affords some amount of protection.
"We make decisions based on data. We don't have any data of giving a single dose and waiting for more than the normal period of time" to give the second dose, Fauci said.
A difficult start to the new year
As Americans rang in the new year, almost 11,000 families grieved the new loss of a loved one to Covid-19.
At least 10,901 Covid-19 deaths were reported in the last three days of 2020, according to Johns Hopkins University. That's about 3,633 deaths a day -- more than the number of lives lost in the 9/11 terrorist attacks in the US.
In less than 11 months, Covid-19 has killed more than 349,000 people in the US. And another 115,000 Americans could die from the disease over the next month, according to projections by the University of Washington's Institute for Health Metrics and Evaluation.
Arkansas reported more than 4,300 new cases Friday.
"This is a record in newly reported cases. We are certainly in the surge after Christmas travel and gatherings," Arkansas Gov. Asa Hutchinson tweeted. "As we enter this new year, our first resolution should be to follow guidelines. We all must do our part."
Texas health officials reported record-high Covid-19 hospitalizations across the state for the fifth day in a row, with more than 12,400 patients.
And Georgia announced a new record high of 8,769 new Covid-19 cases in the state Friday.
Gov. Brian Kemp said the Georgia World Congress Center convention center in downtown Atlanta has been turned into an overflow hospital.
New York added almost 16,500 new cases on Friday, only a day after it hit its highest ever one-day case count.
"As we start 2021, I encourage all New Yorkers to look to their better angels and continue the practices we know stop the spread of this virus - wash your hands, socially distance, and wear a mask," Gov. Andrew Cuomo said in a statement.