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The White House. Accessed Dec. 7, 2021.

Disclosures: Fauci and Walensky report no relevant financial disclosures.
December 07, 2021
2 min read

Omicron ‘might’ cause less severe disease, Fauci says


The White House. Accessed Dec. 7, 2021.

Disclosures: Fauci and Walensky report no relevant financial disclosures.
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National Institute of Allergy and Infectious Diseases Director Anthony S. Fauci, MD, said Tuesday that the omicron variant of SARS-CoV-2 might cause less severe COVID-19 illness.

Anthony S. Fauci

“We are not seeing a very severe profile of disease. In fact, it might be — and I underscore might — be less severe,” Fauci said during a White House press briefing.

 Source: Adobe Stock
Cases of COVID-19 caused by the omicron variant may be less severe. Source: Adobe Stock.

Also Tuesday, Fauci told the Agence France-Presse news agency that omicron is “almost certainly not more severe than delta,” the SARS-CoV-2 variant responsible for the latest wave of infections globally.

His comments came days after the South African Medical Research Council reported that most patients with omicron in a district in Gauteng Province that has been an early hotspot of reported cases did not need supplemental oxygen.

Among 42 patients included in the small report, 29 (70%) were not oxygen dependent. Of the 13 patients in need of supplemental oxygen, nine (21%) were diagnosed with COVID-19-based pneumonia and the other four needed oxygen for other medical reasons, according to the report.

“This is a picture that has not been seen in previous waves,” the report says. “In the beginning of all three previous waves and throughout the course of these waves, there has always only been a sprinkling of patients on room air in the COVID ward and these patients have usually been in the recovery phase waiting for the resolution of a comorbidity prior to discharge.”

Fauci said data regarding the effectiveness of current COVID-19 vaccines against the omicron variant could be available next week.

“We are doing live-virus and pseudo-virus assays that might be ready for interpretation in the middle of next week for the pseudo virus, and probably the end of next week for the live viruses,” he said. “We'll be able to determine whether or not antibodies induced by our vaccines lose their capability of effectiveness with omicron.”

Additionally, animal studies evaluating immune protection and antiviral efficacy are also underway, he said.

The omicron variant has been reported in more than 50 countries and in 19 U.S. states, CDC Director Rochelle P. Walensky, MD, said during the briefing.

Rochelle P. Walensky

“We expect that [case] number to continue to increase,” Walensky said. “While we are still working to understand the severity of omicron, as well as how it responds to therapeutics and vaccines, we anticipate that all of the same measures will — at least in part — provide some protection against omicron.”


Agence France-Presse Top US scientist Fauci: Omicron ‘almost certainly not more severe’ than delta variant. France 24.

CDC. COVID-19. Omicron variant: What you need to know. Accessed Dec. 7, 2021.

SAMRC. Tshwane district omicron variant patient profile – early features. Accessed Dec. 7, 2021.

The White House. Accessed Dec. 7, 2021.