CDC comes under fire for new COVID-19 guidance

The Centers for Disease Control and Prevention (CDC) is under fire from health experts and employee groups who say the new COVID-19 isolation and quarantine guidance has too many holes.

The isolation guidelines announced late Monday apply to everyone, regardless of vaccination status. Some health experts said they worry people will leave isolation while still contagious, and raised questions about the CDC's decision making.

Critics also argue the guidelines ignore the benefits of rapid antigen testing by not requiring those tests, and rely on a one-size-fits-all approach that makes assumptions about the fast-spreading omicron variant that may not be true.

"Regardless of what CDC says, you really should try to obtain an antigen test (I know- easier said than done) and confirm it's negative prior to leaving isolation and quarantine," former Surgeon General Jerome Adams wrote on Twitter.

"There's not a scientist or doctor I've met yet who wouldn't do this for themselves/ their family," Adams wrote.

But officials said the change was necessary in order to keep the country's economic infrastructure from collapsing.

"The reason is that with the sheer volume of new cases that we are having and that we expect to continue with omicron, one of the things we want to be careful of is we don't have so many people out," President Biden's chief medical adviser Anthony Fauci told CNN's Jim Acosta on Monday.

In the early days of the pandemic, CDC recommended a 14-day isolation period for anyone infected with the virus. That eventually changed to 10 days, regardless of a person's vaccination status and whether or not they were symptomatic.

On Monday evening, federal officials cut in half the recommended time needed to isolate after a COVID-19 infection for those not showing symptoms. The CDC also made changes to guidelines on quarantining after exposure to someone who has been infected.

The CDC said that after five days of isolation is up, people should wear a mask around others at all times for another five days. The guidelines did not include a requirement to test before leaving isolation.

The agency has been under pressure from business groups to shorten the isolation period to cut down on staffing shortages. The guidelines announced Monday came less than a week after the CDC made a similar move for health workers.

Notably, Delta Air Lines CEO Ed Bastian sent a letter to the CDC, cosigned by the company's medical adviser and well-known epidemiologist Carlos Del Rio, proposing a five-day isolation period.

But Delta also suggested individuals in isolation would be able end it with an "appropriate testing protocol."

No such language was in the CDC's guidance. Michael Mina, an epidemiologist and chief science officer at eMed, said having no testing requirement was "reckless."

On Twitter, Mina noted that people are testing positive much earlier, because the time from infection to symptom onset is quicker. But that doesn't mean they test negative any sooner; in fact, he said people are staying positive even longer, because they found out earlier.

"Some ppl stay infectious 3 days, Some 12. I absolutely don't want to sit next to someone who turned Positive 5 days ago and hasn't tested [negative]," Mina tweeted.

Some experts have speculated that the CDC didn't include a testing requirement because of the current shortage of rapid tests. In many places, at-home tests are difficult or impossible to find, and even if they are available, the prices are high.

"I wish they just came out and said [the real reason]," Leana Wen, a public health professor at George Washington University, said on CNN Tuesday. "Tests actually are needed to exit isolation, but if we don't even have enough tests right now to test symptomatic people, then we cannot possibly issue a guidance for all of America to exit isolation that way."

The CDC said the change was driven by science showing that the majority of virus transmission occurs early in the course of illness, generally in the first two days prior to onset of symptoms, and the two to three days after.

"CDC's updated recommendations for isolation and quarantine balance what we know about the spread of the virus and the protection provided by vaccination and booster doses. These updates ensure people can safely continue their daily lives," CDC Director Rochelle Walensky said in a statement.

Additionally, the CDC said it was shortening the recommended time for people to quarantine if they are exposed. If you're unvaccinated, or vaccinated but without a booster shot, officials recommend five days of quarantine.

For people who are vaccinated and boosted, the CDC said there's no need to quarantine.

Megan Ranney, an emergency physician and a dean at the Brown University School of Public Health, said she thinks shortening the isolation and quarantine period to five days makes sense, so long as there was a requirement for repeated negative tests first.

However, she questioned why the agency was treating vaccinated and unvaccinated people the same, since studies show the period of infectiousness is shorter for people who have been vaccinated.

Ranney also said the agency needs to make it clear that shortened isolation only applies to people who are asymptomatic. The guidance itself gave mixed messages, allowing for both asymptomatic and for people with symptoms that are "resolving."

"If the rules truly are that if you are asymptomatic, you can shorten your isolation. That's there. And that's backed up by the science," Ranney said. "That's a very different thing from being quote unquote, mildly symptomatic."