MILWAUKEE (CBS) — The State of Wisconsin is investigating an outbreak of COVID-19 at a wedding in Milwaukee, in which five out of 12 people were infected with the omicron variant.

The people who were infected were not residents of Wisconsin – they were all California residents who came to the wedding on Nov. 27, according to the Wisconsin Department of Health Services.

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A California state lab learned five of the 12 infected people were infected with the omicron variant.

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The 12 people diagnosed with COVID-19 were between the ages of 18 and 49. All were vaccinated, and most had received boosters. They are mildly symptomatic, and none have been hospitalized, the state said.

The Wisconsin Department of Public Health Services and the City of Milwaukee Health Department have reached out to all Wisconsin residents who were close contacts, and isolation and quarantine protocols have been followed, the state said.

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“Although the news that this variant is continuing to spread throughout the country is concerning, it should not be a cause for panic. We know COVID-19 vaccines are effective at preventing serious illness and death,” Wisconsin Department of Health Services Secretary-designee Karen Timberlake said in a news release. “That’s why it’s critical that all eligible Wisconsinites get vaccinated or get their booster as soon as possible and follow public health best practices to keep ourselves and our loved ones safe.”

CBS 2 Chicago Staff