OAKLAND (AP) — Public health officials say at least five people in Northern California have contracted the omicron variant of COVID-19, and the outbreak is linked to a wedding in Wisconsin last month.

The outbreak was announced Friday — just two days after the first U.S. case of the omicron variant was identified in California.

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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.

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The five people are among a group of 12 who have tested positive for COVID-19 and are linked to a Nov. 27 wedding in Wisconsin.

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