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CDC cuts isolation time recommended for people with asymptomatic coronavirus infections

Thousands of flights across the globe were canceled over the Christmas weekend as a result of staffing shortages related to the surge in omicron infections. (Michael Reynolds/EPA-EFE/Shutterstock)

Federal health officials on Monday shortened the recommended time Americans infected with the coronavirus should isolate from 10 days to five if they are asymptomatic — a decision they said was driven by a growing body of research about when people are most infectious.

The updated guidance from the Centers for Disease Control and Prevention comes as the nation is contending with a new coronavirus wave driven by the highly transmissible omicron variant, which has sent infections soaring to levels not seen since last winter and led to cancellations of thousands of holiday flights.

Airline and other industry officials have been calling on the agency to shorten recommended quarantine and isolation times. They said the slew of flight cancellations were largely driven by employees who tested positive for the virus and were isolating for 10 days. Airline officials, as well as those from other industries, have expressed concern that omicron’s transmissibility would make it impossible to keep businesses running if they followed earlier guidelines.

As part of its update, the CDC also cut the recommended quarantine time to five days for those exposed to the coronavirus who are not yet boosted. It recommended such people wear masks around others for an additional five days.

The agency said those exposed to the infection who have received booster shots do not need to quarantine, but should wear a mask for 10 days.

“These updates ensure people can safely continue their daily lives,” CDC director Rochelle Walensky said in a statement. “The omicron variant is spreading quickly and has the potential to impact all facets of our society. 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.”

The agency said the decision was driven by research that has shown that most transmission occurs early in the course of a person’s illness, typically in the one to two days before the onset of symptoms and, then, for two to three days afterward. Health officials also recommended that those exposed get tested five days after their exposure.

Business groups applauded the update, but some health experts were incensed that the agency would reduce the isolation period without first requiring people to get a negative coronavirus test result.

“I absolutely don’t want to sit next to someone who turned Positive 5 days ago and hasn’t tested [negative],” tweeted epidemiologist Michael Mina, an assistant professor at Harvard T.H. Chan School of Public Health, calling the guidance “reckless.”

Other health experts, however, argued the changes are essential to minimize the pandemic’s disruptions to daily life.

“The new guidance reflects a growing reality that we’re going to have to learn to live with covid as a persistent risk, and can’t let it shut down society,” said Scott Gottlieb, a Pfizer board member and former Food and Drug Administration commissioner.

Gottlieb added that the most prudent practice for most people is to apply the new guidance to “your own level of contagion.” “We know that those who are vaccinated, and those who were previously infected and vaccinated, are more likely to shed virus for shorter periods of time,” he added.

Last week, the CDC cut isolation and quarantine times for health-care workers in an effort to stave off staff shortages. That guidance said that health-care officials with asymptomatic infections could return to work after seven days, and said isolation times could be shortened further if there are staffing shortages.

While the omicron variant is more transmissible, it is far less likely to send people to the hospital than delta, early international studies have shown. Those who are vaccinated and especially those who are boosted are likely to experience only mild symptoms, experts said.

The seven-day average of new daily cases in the U.S. was more than 222,000 on Monday, up more than 52 percent from the seven-day average a week ago, according to The Washington Post covid tracker. The seven-day average of daily deaths was at 1,415 on Monday.