The Centers for Disease Control and Prevention estimated that the Omicron variant now accounts for roughly 59 percent of all Covid cases in the United States, a significant decrease from the agency’s previous estimate. Experts said that the update shows how difficult it is to track the rapidly spreading variant in real-time and how poorly the agency communicates its uncertainty.
The C.D.C. According to the C.D.C., Omicron was responsible for approximately 73% of variants that circulated in the United States during the week ending December 18. In its revision, however, the agency stated that Omicron accounted for approximately 23 per cent of cases in that week.
Delta, which has dominated U.S. infected since summer, reigned that week. This could indicate that many current Covid hospitalizations are due to infections from Delta, Dr. Scott Gottlieb (a former commissioner of Food and Drug Administration) said. suggestedFollow us on Twitter. Hospitalizations are often several weeks behind the initial infection.
Experts said they were not surprised by the revisions, given that the C.D.C.’s estimates are rough guesses, with a wide range of possible values known as “confidence intervals.” Cases of Omicron can only be confirmed by genetic sequencing, which is performed on just a portion of samples across the country.
Omicron continues to grow at a rapid pace.
However, they claimed that the C.D.C. However, they said that the C.D.C. did not do a good job communicating the uncertainty of its estimates.
“The 73 percent got a lot more attention than the confidence intervals, and I think this is one example among many where scientists are trying to project an air of confidence about what’s going to happen,” said David O’Connor, a virologist at the University of Wisconsin-Madison.
Dr. O’Connor said he initially thought the initial 73 percent point estimate “seemed high.” The agency came up with the estimate based on a “relatively small number of sequences,” he added.
“It’s like playing Name That Tune, and trying to say, based on just the first note, if the song is Ice Ice Baby by Vanilla Ice, or Under Pressure,” Dr. O’Connor said. “Without more data it can be really hard to know which one it’s going to be.”
Experts also said that the new estimate at 59 percent is an estimate and will likely be adjusted in future weeks.
“I just want people to be very aware that that is an estimate, that’s not actually from sequence-confirmed cases,” said Nathan Grubaugh, an epidemiologist at the Yale School of Public Health. “With Omicron in particular, it’s been very difficult to have any sort of projections, because things are changing just so so rapidly.”
Dr. Grubaugh, who is examining probable Omicron cases in Connecticut, stated that the variant is present in more than 80 per cent of the cases, but he also pointed out that the country can be heterogenous, and that the variant could have a different prevalence at different locations.
“I don’t know how the C.D.C. built their algorithm, but human beings made these programs, and humans are fallible,” said Massimo Caputi, a molecular virologist at the Florida Atlantic University School of Medicine. “At the end of the day you can predict as much as you want but you need to look at the numbers you have in your hand.”
Dr. O’Connor, who is tracking Omicron in Wisconsin, said the variant made up half of cases on the University of Wisconsin–Madison campus in just three days. “If I was making a betting prediction, it wasn’t so much that the number 73 percent was wrong, but the timing to get there was wrong,” he said.
These predictions will likely become more accurate as more data is collected on Omicron.
To distribute Covid treatments efficiently, it will take more precise numbers. One of the great challenges of Omicron is the variant’s ability to thwart two of the three monoclonal antibody treatments, which can prevent serious illness in Covid-19 patients. As such, some hospitals have begun scaling back these treatments; administrators at NewYork-Presbyterian, N.Y.U. Langone, Mount Sinai and others stated that they would discontinue giving Omicron-resistant treatments to patients. The drugs could still be helpful to those infected with Delta.
“If you still have those Delta cases, discontinuing monoclonals means all those people who would have benefited from them won’t be receiving them at all,” Dr. O’Connor said.
Dr. O’Connor said scientists and health care providers need to do a better job of communicating the uncertainty in the predications they share with the public. “Having the humility to acknowledge that there’s a lot that no one knows and is unknowable right now is going to be really important.”
Source: NY Times