CDC confirms Omicron less severe than other variants

COVID-19 viruses under the microscope
COVID-19 viruses under the microscope


Thirty-one states, as well as Washington, DC and Puerto Rico, are reporting decreasing or plateauing new COVID-19 case averages, ABC News reports, signaling that the massive surge caused by the Omicron (B.1.1.529) variant may be receding.

New data published today in Morbidity and Mortality Weekly Report show that illnesses caused by Omicron are less severe than previous variants, but have still strained US healthcare systems due to the sheer volume of cases.

Omicron was first confirmed in the United States on Dec 1, 2021, and as of Jan 15, 2022, represented 99.5% of all sequenced viruses in the country. To gauge the severity of cases, the Centers for Disease Control and Prevention (CDC) compared that 6-week timeframe with cases and outcomes from Dec 1, 2020, through Feb 28, 2021 (winter 2020-21, when the wild-type strain was predominant), and Jul 15 to Oct 31, 2021, when Delta (B1617.2) was the most dominant variant.

"The highest daily 7-day moving average to date of cases (798,976 daily cases during January 9–15, 2022), emergency department (ED) visits (48,238), and admissions (21,586) were reported during the Omicron period, however, the highest daily 7-day moving average of deaths (1,854) was lower than during previous periods," the authors wrote.

The ratio of peak emergency department visits, hospital admissions, and deaths to case, were all lower in Omicron than other variants.

The findings confirm data from South Africa, the United Kingdom, and health systems in Texas and California.

More than 1.1 million new pediatric cases

According to the latest update from the American Academy of Pediatrics (AAP), nearly 1,151,000 child COVID-19 cases were reported from Jan 13 to 20, a 17% increase over the previous week.

"Over 10.6 million children have tested positive for COVID-19 since the onset of the pandemic; Over 2 million of these cases have been added in the past 2 weeks," the AAP said in its report. This is the 24th week in a row with child cases totaling 100,000 or more.

The United States reported 1,007,511 new COVID-19 cases yesterday and 1,963 deaths, according to the Johns Hopkins COVID-19 tracker.

The 7-day average of new daily cases is 668,312, with 2,083 daily deaths, according to the New York Times tracker.

Pfizer announces Omicron booster trial

Today, Pfizer-BioNTech announced the first trial meant to evaluate the safety, tolerability, and immunogenicity of an Omicron-based vaccine candidate in healthy adults 18 to 55 years old.

"While current research and real-world data show that boosters continue to provide a high level of protection against severe disease and hospitalization with Omicron, we recognize the need to be prepared in the event this protection wanes over time and to potentially help address Omicron and new variants in the future," said Kathrin U. Jansen, PhD, senior vice president and head of vaccine research & development at Pfizer, in a press release.

The study will compare an Omicron-specific vaccine with the current Pfizer COVID-19 vaccine. As many as 1,420 participants are expected to enroll in the trial.

The CDC COVID Data Tracker shows that 63.4% of Americans are fully vaccinated against COVID-19, 75.6% have received at least one dose of vaccine, and 40.1% of vaccinated Americans have received a booster dose, which may be crucial for offering protection against Omicron.

In related news, Florida is closing all of its monoclonal antibody treatment sites, citing the Food and Drug Administration's decision to limit use of treatments found to be ineffective against Omicron, CNN reports.

Other US developments

  • Idaho public health officials yesterday activated crisis standards of care for much of southern Idaho, citing major staffing and blood supply shortages, according to the Associated Press.

  • Two COVID-19 cases caused by a subvariant of Omicron, BA.2, were detected earlier this month in Washington, Fox News reports

  • Free N95 masks from the Strategic National Stockpile are now available at some US supermarket chains, and more will be arriving later this week, the Washington Post reported today. 

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