Omicron now accounts for 3% of US coronavirus cases

The Omicron variant has accounted for 3 percent of coronavirus cases in the US, the Centers for Disease Control and Prevention (CDC) said Tuesday, an increase from the previous week of 0.4 percent.

Health officials said the number is likely to increase quickly, given the pattern in other countries. For example, officials in the UK said Omicron represents more than 1 in 5 coronavirus cases there and that the number of cases from the variant is doubling every two to three days.

The variant has been identified in at least 30 states and Washington DC, according to the CDC. In New York and New Jersey, the federal agency said Omicron is already at 13 percent of sequenced cases.

"While it is rapidly increasing, we have the tools needed to fight #COVID19," CDC Director Rochelle Walensky wrote on Twitter on Tuesday. "Get vaccinated, get boosted."

The Delta variant still causes 97 percent of cases in the US, according to the CDC.

Nationally, the seven-day average for new US cases is near 120,000, up from a recent drop to around 71,000 in late October, according to data from Johns Hopkins University.

The Omicron variant reduces the effectiveness of Pfizer-BioNTech's COVID-19 vaccine, but the vaccine can still lower the risk of hospital admission, according to the first large real-world study published Tuesday.

The study, by the largest private health insurer in South Africa, Discovery Ltd, found that Omicron reduced vaccine effectiveness against infection to 33 percent from 80 percent for Delta.

Still, the Pfizer-BioNTech vaccine's efficacy against severe illness and hospitalization falls to 70 percent from 93 percent, the study found.

The study also found that people infected with the Delta variant have a 40 percent relative risk of contracting the Omicron variant, while those infected during the Beta-driven wave at the beginning of 2020 faced a 60 percent chance of reinfection with Omicron.

Of 43 coronavirus cases caused by the Omicron variant identified in the United States as of Friday were in people who were fully vaccinated, and a third of them had received a booster dose, according to a CDC report.

The CDC said that 34 people had been fully vaccinated. Fourteen of them also had received a booster shot, although five of those cases occurred fewer than 14 days after the additional shot.

Pfizer said Tuesday that its experimental pill — known as Paxlovid — reduced the risk of hospitalization and death from COVID-19 by 89 percent if given within three days of the onset of symptoms. Pfizer also said that a separate laboratory testing shows that the drug retains its potency against the Omicron variant.

"We are confident that, if authorized or approved, this potential treatment could be a critical tool to help quell the pandemic," Albert Bourla, Pfizer's CEO, said in a statement.

The Food and Drug Administration is expected to soon rule on whether to authorize the treatment.

Meanwhile, Kroger, the US' largest supermarket operator, said Tuesday that it will take away two weeks of paid leave for unvaccinated employees who get COVID-19 and will require some of them to pay a $50 monthly health insurance surcharge starting Jan 1, The Wall Street Journal reported.

The US Air Force has removed 27 people for refusing to get the COVID-19 vaccine, a spokeswoman said Monday, marking the US military's first dismissals of those who refuse the shots.

The Air Force gave its members until Nov 2 to get the vaccine, and thousands have either refused or sought an exemption. Air Force spokeswoman Ann Stefanek acknowledged that those dismissed Monday were the first active-duty Air Force members to be discharged for reasons involving the vaccine.

More than 94 percent of the Air Force is fully vaccinated, according to the service's data.

Reuters contributed to this story.