By Marie Rosenthal
In less than one month, omicron has overtaken delta to become the dominant SARS-CoV-2 strain in the United States. As of Dec. 18, 73.2% of COVID-19 cases were caused by omicron versus 26.6% caused by delta, which had been the predominant strain in the United States for months.
Public health officials are concerned about how quickly omicron has spread in the United States, but how virulent the variant will prove to be is still largely unknown. However, there has been an uptick