Delta Air Lines updates its Covid-19 policies after the C.D.C.’s new guidance.

Delta Air Lines has updated its policies for workers who get sick with the coronavirus, soon after the Centers for Disease Control and Prevention shortened its recommended isolation period for Americans infected with Covid-19.

Delta was one of the first companies to adapt to the updated guidance, which it had publicly called on the C.D.C. to do. The Biden administration and major companies have said shortening the isolation period will help keep society functioning, but unions have worried it could allow companies to pressure employees to come back to work.

The airline’s new policy, dated Tuesday, provides five days of paid leave for workers who test positive for the coronavirus to isolate, according to an internal communication to company leaders obtained by The New York Times. And it encourages, but does not require, a Covid test to go back to work, going a step further than the C.D.C. guidance, which does not include a recommendation for additional testing. Delta’s new protocols make no mention of whether returning employees should have improving symptoms, as suggested by the C.D.C.

Many airlines have had to cancel a spate of flights during the busy holiday travel season, blaming staff shortages caused by a spike in infections. Delta and other airlines asked the C.D.C. last week to update its isolation recommendations, which some public health officials said were outdated. Delta warned that the 10-day isolation period that the C.D.C. put in place last year could “significantly impact” its operations as the Omicron variant of the virus rapidly spreads, and it suggested a five-day isolation period with an “appropriate testing protocol.”

A spokesman for the airline said Delta is “strongly recommending our people get tested prior to returning to work, regardless of symptoms (or absence of).” He did not say whether the airline would request to see the results of any test. Delta requires all employees to wear masks in work areas, in airports and on flights.

Delta will extend its five days of Covid-specific paid time off, which it offers only to fully vaccinated individuals, by two additional days if an employee tests positive at the end of the initial isolation period, according to the memo. It previously offered 10 days of paid leave for workers with Covid.

The airline also put in place new guidelines for workers who are exposed to Covid for long periods of time without the protection of masks. (The guidelines echo new parameters outlined by the C.D.C.) Those who have received a booster shot or are recently fully vaccinated do not need to quarantine. Those who are unvaccinated or who received their primary shots longer ago should quarantine for five days after a high-risk exposure.

The Coronavirus Pandemic: Key Things to Know

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The U.S. surge The U.S. record for daily coronavirus cases has been broken, as two highly contagious variants — Delta and Omicron — have spread across the country. The seven-day average of U.S. cases topped 267,000 on Tuesday, according to a New York Times database.

New C.D.C. guidelines Hoping to prevent further disruptions to daily life, the C.D.C. reduced the period that certain infected Americans must sequester to five days from 10. This change applies only to those without symptoms, or those without fevers whose other symptoms are improving.

Delta said that 97 percent of its work force is vaccinated. While other carriers, like United Airlines, have mandated vaccines for their work force, Delta has opted to charge unvaccinated workers an additional $200 a month to remain on the company’s health plan.

Some scientists have been critical of the C.D.C.’s decision to shorten the isolation period without a requirement for testing. The Association of Flight Attendants is asking airlines to require a negative test for employees at the end of a five-day isolation period. It is also asking that unvaccinated workers be required to abide by a 10-day isolation period and that employees be provided with high-quality masks for at least five days after returning to work.