At least five people in northern California have contracted the omicron variant of the coronavirus, and the outbreak is linked to a marriage in Wisconsin last month, public health officials said Friday.
The outbreak was announced just two days after the first US 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, if it makes people more seriously ill, and if it can thwart the vaccine.
The five people who have confirmed cases of omicron are among a group of 12 vaccinated people in Alameda County who have tested positive for COVID-19, according to the Alameda County Public Health Department. They are linked to a November 27 wedding in Wisconsin, “which one of these people attended on returning from an international trip,” the agency said.
People have been vaccinated and have “mildly symptomatic cases”. Genomic sequencing of the remaining seven cases is not yet complete.
Public health officials did not say where and when the person traveled overseas, nor did they immediately respond to questions about the Wisconsin marriage.
Officials said “most” of the 12 people had received boosters; they are between 18 and 49 years old.
The Biden administration decided late last month to restrict travel from southern Africa, where the variant was first identified and had spread. Clusters of cases have also been identified in about two dozen other countries.