Genomic surveillance data indicates the omicron COVID-19 variant accounts for about 3 percent of new U.S. cases, CDC Director Rochelle Walensky, MD, told NBC's Today on Dec. 14.
The strain has been detected in at least 33 states and accounts for 13 percent of new cases in New Jersey and New York.
"We're starting to see some early data that is demonstrating some decreased severity — shorter lengths of stay, fewer people on oxygen, fewer people in the intensive care unit — but I also want to emphasize if you have more and more people who have disease, even if you have fewer people that get sick from it, you still have a lot of people who are getting sick, so really we want to make sure we keep all those keep prevention measures — vaccination, boosters — in place," Dr. Walensky said.
Preliminary findings suggest omicron causes less severe illness than earlier variants. It is more transmissible, however, and a new study published Dec. 14 based on information from 211,000 COVID-19 cases in South Africa also supports that indication. The risk of hospitalization among people who contracted COVID-19 during a surge in omicron cases was 29 percent lower relative to the initial wave in March 2020.
The same study also found omicron was more resistant to Pfizer-BioNTech's vaccine, which provided about 33 percent protection against infection. Still, the vaccine offered 70 percent protection against hospitalization.