Image of Anthony Fauci, director of NIAID; Image credit: NIAID
Anthony Fauci, M.D., Image credit: NIAID

Early data suggest that the coronavirus omicron variant is highly transmissible but may cause less severe illness than the delta variant, the White House’s top infectious disease expert reports.

In a Tuesday press briefing, Anthony Fauci, M.D., said that while more information is needed, omicron cases appear to have led to fewer hospitalizations and that patients have been less likely to need oxygen, according to U.S. News & World Report.

South Africa, where the new variant was first detected, has seen omicron overtake delta at lightning speed. Researchers in that country have reported a “vertical spike” in cases that are almost exclusively due to omicron, Fauci told CNN Tuesday. 

In October, delta accounted for 80% of all coronavirus samples sequenced in South Africa and omicron wasn’t yet detected. But by November, 75% of sequenced viruses were omicron and 22% were delta, according to MedScape. 

Regarding disease severity, one concern among scientists is that the variant has mutated in a way that will help it to evade virus-fighting antibodies, thereby making it resistant to natural immunity, the medical news outlet reported.

But the rate of recent hospitalizations for COVID-19 in South Africa have not matched the increase in cases. That’s an encouraging sign, according to Fauci, but he said that more evidence is needed to make further definitive judgements about the variant’s effects. Americans should “hold judgment until we get more experience,” he said on CNN.

The question for Americans now is what will happen when omicron competes with delta, the dominant variant that continues to cause outbreaks nationwide, Fauci added.

In the meantime, vaccinated Americans are getting “quite good protection” against delta, Fauci said. And there is reason to feel confident that there may also be “considerable protection” against omicron, especially with a COVID-19 booster shot, he noted.