People line up for at a CDC mobile COVID-19 testing location Dec. 23, 2021, in Queens, New York. (AP Photo/Frank Franklin II)
Paul Best | Fox News
Delta was responsible for just 4.6% of all new cases for the week that ended Jan. 1.
The new omicron variant of COVID-19 has nearly made delta obsolete, as it was responsible for 95.4% of all new cases in the week that ended Jan. 1, according to CDC data released Tuesday.
It took only about a month for the new variant to displace delta, as the first case of omicron was detected in the United States on Dec. 1 and it was responsible for just 0.6% of new cases for the week that ended Dec. 4.
Omicron was responsible for 8% of cases by Dec. 11, 37.9% of cases by Dec. 18, and 77% of cases by Dec. 25.
Delta is still dominant in parts of New England and the Plains, but omicron is dominant everywhere else, according to CDC data.
The rise of omicron has coincided with a record surge in new COVID-19 cases, as the seven-day average for new cases stood at 316,277 on Dec. 29.
The United States reported 1,082,549 new cases on Monday, according to Johns Hopkins University, but that number may be elevated due to a backlog of cases over the holidays and weekend.
Multiple studies have shown that omicron’s rapid spread may be due to the variant’s ability to evade immunity offered by both vaccines and previous infection.
Nurse Mary Ezzat prepares to administer a Pfizer COVID-19 booster shot on Aug. 19, 2021, at UCI Medical Center in Orange, California. (Jeff Gritchen/The Orange County Register via AP)
While it may be spreading faster than previous variants, omicron has been associated with milder disease.
A study conducted by Discovery Health in South Africa, where omicron was first identified, found that hospital admissions for adults with the new variant were 29% lower than for those with delta.
Researchers at the LKS Faculty of Medicine at The University of Hong Kong found that omicron replicates 70 times faster than delta in the human bronchus, but 10 times slower in lung tissue, which may explain why it spreads more rapidly but is responsible for less severe disease.
Vaccines are still effective against illness from omicron, according to a University of Copenhagen study that found a booster shot offered 86% protection against symptoms and 98% protection against severe disease.