(NewsNation Now) — U.S. health officials are defending their updated recommendation that halves quarantine time for those infected with COVID-19 after some doctors, including at least one national health leader, panned it as inadequate.

Officials with the Centers for Disease Control and Prevention, along with other health leaders, say it’s a practical adjustment as cases soar.

“People with important jobs in keeping society functioning may not be able to come to work if they’re all out for a full 10 days,” Dr. Anthony Fauci told Nexstar’s Reshad Hudson on Tuesday.

Under the new rules, all Americans who test positive, regardless of vaccination status, should isolate themselves for five days and wear a mask for another five, even among family at home. Boosted Americans who are close contacts of a confirmed case do not need to isolate, provided they’re wearing masks for 10 days after they were exposed.

“Not all of those cases are going to be severe. In fact, many are going to be asymptomatic,” CDC Director Dr. Rochelle Walensky said Monday. “We want to make sure there is a mechanism by which we can safely continue to keep society functioning while following the science.”

CDC officials said the guidance is in keeping with growing evidence that people with the virus are most infectious in the first few days.

Still, some doctors are concerned people who are still contagious will infect others.

“It’s frankly reckless to proceed like this,” said Dr. Eric Topol, founder and director of the Scripps Research Translational Institute. “Using a rapid test or some type of test to validate that the person isn’t infectious (before mingling with others) is vital.”

“There’s no evidence, no data to support this,” he added.

Finding a test in the U.S. can be difficult. Fauci said there would be more tests in January, and President Joe Biden has pledged to provide 500 million free tests. However, that doesn’t guarantee every American more than one test.

The CDC is also facing criticism for revising its previous report saying more than 70% of cases during the week ending Dec. 18 were omicron infections. Tuesday, they said the real number was less than 23%.

They also released data for the week ending on Christmas that shows omicron accounted for around 59% of U.S. cases. 

“We had more data come in from that timeframe and there was a reduced proportion of omicron,” a CDC spokesperson told Reuters. “It’s important to note that we’re still seeing a steady increase in the proportion of omicron.”

The new recommendations come as several of America’s biggest cities are preparing vaccine mandates for indoor activities. New York City’s went into effect Monday. Chicago’s will start Jan 3, followed by Washington, D.C., and Boston on Jan 15.

The patchwork of mandates does not include uniform execution or enforcement. Some cities will use the Clear app to allow residents to store their vaccine status digitally, while others have no standard.

NewsNation reached out to the White House and CDC asking if there are plans to roll out a national digital system, but they haven’t responded.

Americans are also planning New Year’s Eve parties. Most health officials are not discouraging them, but Dr. Susan Bleasdale, medical director of infection prevention at the University of Illinois, said there’s no way to eliminate the risk of spread, even with testing.

“Adding a test before you gather is helpful,” she said on “NewsNation Prime” on Tuesday. “However, we have seen some ongoing transmission from the most recent Christmas weekend that people have gathered with testing before and then within 24 hours, someone has become symptomatic.”

The surge in cases is also putting a strain on schools. New York City reported a fourfold increase in pediatric hospitalizations for COVID-19 since Dec. 5. The majority of hospitalized children are unvaccinated.

Only children 5 and older are eligible for vaccination now, and shots for younger kids are not expected soon.

“By the time we get enough data to make any kind of authorization, it likely will not be until a few months into 2022,” Fauci said.