The U.S. Centers for Disease Control and Prevention severely revised its estimate of the prevalence of the Omicron variant on Tuesday.
Previously the CDC had estimated that as many as 73.2% of coronavirus cases nationwide were due to the Omicron variant on Dec. 18. The new estimate dials it down to 22.5% for the same date.
As of Dec. 25, the CDC estimates that Omicron accounts for 58.6% of coronavirus cases.
“There was a wide predictive interval posted in last week’s chart, in part because of the speed at which Omicron was increasing,” explained CDC spokesperson Jasmine Reed to Politico.
“We had more data come in from that timeframe and there was a reduced proportion of Omicron," she added.
Former FDA Commissioner Scott Gottlieb tweeted a response to the new finding.
"Setting aside the question of how the initial estimate was so inaccurate, if CDC’s new estimate of #Omicron prevalence is precise then it suggests that a good portion of the current hospitalizations we’re seeing from Covid may still be driven by Delta infections," wrote Gottlieb.
The revision came a day after the CDC also changed its guidance on isolation and quarantine recommendations for those who tested positive for the coronavirus. Previously to the revision on Monday, the CDC called for people to quarantine for ten days, but it has since said that 5 days would be sufficient. For those not exhibiting symptoms and being fully vaccinated, no isolation was necessary.
Some criticized the CDC for that change and accused health officials of fitting their recommendations to political and economic pressures rather than the science.
The newest spike in coronavirus infections in the U.S. reached a seven-day daily average of 243,000 new cases on Tuesday. The previous peak of infections came in January with a seven-day daily average of 251,000 new cases.
Here's more about the CDC revisions:
Omicron not as prevalent as first thought but remains dominant variant: CDC www.youtube.com