The Centers for Disease Control revised its estimate for the prevalence of the Omicron variant in the United States, dramatically dropping the percentage of coronavirus infections that are assumed to be caused by Omicron.
Politico reported that the CDC is previously estimated that of all the coronavirus cases as of December 25, 58.6% of them were Omicron infections. Now, the public healthy agency is suggesting the Omicron strain accounted for 41.5% cases, and the still prevalent Delta variant made up 41.1% of infections.
In further revision, the CDC is now saying the infectious Omicron variant made up 22.5% of cases as of December 18, as opposed to the 73.2% it previously suggested.
The agency said the revision was due to previous data that relied on predictions of how rapidly Omicron was being transmitted, which was revised when information from the timeframe became available.
“There was a wide predictive interval posted in last week’s chart, in part because of the speed at which Omicron was increasing,” an agency representative told Politico. “We had more data come in from that timeframe and there was a reduced proportion of Omicron.”
Former FDA Commissioner Scott Gottlieb said this could mean the current rise in hospitalizations is being driven by the Delta variant.
“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,” he tweeted.
The U.S. is recording more than 200,000 Covid infections daily, even as national air travel levels have hit and even surpassed pre-pandemic numbers.