The decision by federal health officials to shorten isolation periods for Americans infected with the coronavirus drew both tempered support and intense opposition from scientists Tuesday, particularly over the absence of a testing requirement and fears that the omission could hasten the spread of the highly contagious omicron variant.
The new guidance, coming amid a crush of new infections that has starved many hospitals of workers, seemed to some scientists like a necessary step to shore up workforces in essential industries. And encouraging people to leave isolation early after testing negative could spare them the hardships of prolonged periods at home.
But letting hundreds of thousands of infected people forgo those tests — even if, crucially, their symptoms were not entirely gone — risks seeding new cases and heaping even more pressure on already overburdened health systems, experts said in interviews Tuesday.
“To me, this feels honestly more about economics than about the science,” said Yonatan Grad, an associate professor of immunology and infectious diseases at the Harvard T.H. Chan School of Public Health, who has tracked coronavirus infections in the NBA.
“I suspect what it will do is result in at least some people emerging from isolation more quickly, and so there’ll be more opportunities for transmission and that of course will accelerate the spread of COVID-19,” he added.
Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Tuesday that the new guidance had been necessitated by the volume of people about to be infected.
In a series of holiday weekend meetings, she said, agency officials pored over transmissibility data for past variants and signs that omicron caused less severe illness. But ultimately, Walensky said, she decided that rapid tests were not effective enough at diagnosing infectiousness in people.
The CDC’s recommendations cut isolation periods for infected people from 10 days to five. The agency did not recommend rapid testing before people left isolation.
But some scientists maintain that rapid tests are the most convenient indication of whether or not someone remains contagious.
President Joe Biden has promised to make 500 million tests available free of charge, but it is not clear how quickly they will be shipped.