The data from South Africa on the new Omicron coronaviruses variant is encouraging.
Fauci told CNN's State of the Nation Sunday that it's too early to tell if Omicron causes only mild infections.
Fauci said that so far there was no great degree of severity to the Omicron variant, which has a high number of mutations in the part of the virus that attach to human cells.
Fauci said that they need to be careful before they make any determinations on whether it's less severe than Delta. The most common variant in the US is the Delta variant, which is highly infectious and has a number of genes that help it avoid the immune response.
Fauci said that Omicron was becoming the most common variant in South Africa, and that it was a country that sounded the alarm less than two weeks ago.
The average number of new daily COVID-19 cases per million in South Africa has increased more than 17 fold from November 22 to Sunday.
According to official figures, 3,255 South Africans were admitted to hospital with COVID-19 on Saturday. The data showed that there were over 16,000 new COVID-19 cases that day.
Experts are still trying to figure out if Omicron's unusual genes make it more deadly or infectious than Delta, and if it can evade vaccines.
It was too early to say if the Omicron variant caused more disease than Delta, but initial reports suggested it did, according to Dr. Maria Van Kerkhove, COVID-19 technical lead at the World Health Organization and US infectious disease doctor.
Kerkhove warned that it was important to act fast and control the spread of COVID-19 even if it was mild. More hospitalizations can be a result of more cases. More hospitalization can lead to more death. She said that they don't want to see that happening on top of an already different situation.
Fauci said that Delta was responsible for most of the new COVID-19 cases in the US. He said that 15 US states have detected Omicron.
Fauci said that boosters are going to be important in determining whether the US can handle both versions. According to the Centers for Disease Control and Prevention, 23% of Americans have had a booster shot.
