At least five people in Northern California have contracted the omicron variant of the coronavirus, and the outbreak is linked to a wedding in Wisconsin last month, public health officials said Friday.
The outbreak was announced just two days after the first U.S. case of the omicron variant was identified in California.
Much remains unknown about the new variant, including whether it is more contagious than previous strains, whether it makes people more seriously ill, and whether it can thwart the vaccine.
The five people who have confirmed omicron cases are part of a group of 12 vaccinated people in Alameda County who have tested positive for COVID-19, according to the Alameda County Department of Public Health. They are linked to a Nov. 27 wedding in Wisconsin, “which one of these individuals attended upon return from international travel,” the agency said.
Get Chicago local news, weather forecasts, sports and entertainment stories to your inbox. Sign up for NBC Chicago newsletters.
The people were vaccinated and have “mildly symptomatic cases." Genomic sequencing for the remaining seven cases has not yet been completed.
Public health officials have not said where and when the person traveled internationally, nor did they immediately respond to questions about the Wisconsin wedding.
Officials said "most" of the 12 people had received boosters; they are between 18 and 49 years old.
The Biden administration moved late last month to restrict travel from southern Africa, where the variant was first identified and had been widespread. Clusters of cases have also been identified in about two dozen other nations.