New data released by the Centers for Disease Control and Prevention (CDC) shows that cases of the newly discovered omicron variant are on the rise in the United States, but the delta variant still accounts for the vast majority of COVID-19 cases in the country.

What You Need To Know

  • New CDC data shows that omicron variant cases are on the rise in the U.S.

  • Omicron cases account for nearly 3% of all new COVID-19 cases nationwide, per the CDC, up from 0.4% the week prior

  • Early data also shows that the omicron variant appears to cause more mild cases than previous strains of the coronavirus variants — even though it does appear to be better at evading vaccines

  • The new figures come as cases are on the rise nationwide: The U.S. on Monday surpassed 50 million total known coronavirus cases nationwide

For the week ending on Dec. 4, the omicron variant accounted for less than 1% — 0.4% — of all new cases in the United States. The next week, omicron cases jumped to account for nearly 3% of all new COVID-19 cases nationwide.

For comparison, the highly transmissible delta accounted for nearly 97% of cases nationwide the week ending on Dec. 11.

These figures are estimates, but it does show that omicron cases are growing, and could potentially overtake delta as the dominant strain in the country in the coming weeks. 

It also comes as cases are on the rise nationwide — the U.S. on Monday surpassed 50 million total known coronavirus cases, and the country approaches the grim milestone of 800,000 COVID-19 deaths.

But early data also shows that the omicron variant appears to cause more mild cases than previous strains of the coronavirus variants — even though it does appear to be better at evading vaccines.

Discovery Health, South Africa’s largest private health insurer, and the South African Medical Research Council, conducted a study which showed that the Pfizer-BioNTech vaccine is 33% effective at preventing infection during the country’s wave of cases, driven by the omicron variant. But the study also found that the two-dose mRNA vaccine is 70% effective at preventing hospitalization. (The study did not look at booster shots.)

While promising, it is worth noting that such data is still preliminary, and health officials are imploring unvaccinated people to get vaccinated against the coronavirus, and urging those vaccinated to reinforce their protection with a booster shot.

"If I sound a little frustrated, perhaps I am," New York Gov. Kathy Hochul said Tuesday morning said of a surge of cases in the state. Since Thanksgiving, COVID-19 cases have increased by 58% in in New York, and hospitalizations due to the virus increased by 70%. 

Testing shows that omicron cases are on the rise in Washington State, according to University of Washington researchers.

"It’s clearly looking like it’s rising really quickly," Dr. Pavitra Roychoudhury, a researcher at the university, told the New York Times.

Researchers in countries like the United Kingdom, Denmark and Norway have, in recent days, made grim predictions about the variant's speed and spread. 

"Omicron is spreading at a rate we have not seen with any previous variant," World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus said Tuesday, noting that the strain has been reported in 77 countries, and is likely in most countries.

"Even if omicron does cause less severe disease, the sheer number of cases could once again overwhelm unprepared health systems," he warned, noting that health officials have expressed concerns "that people are dismissing omicron as mild"