BERKELEY (CBS SF) — At least five people in Alameda County have been diagnosed with the omicron variant, with the five among 12 local COVID cases all linked to a wedding last week, health authorities announced Friday.

The Alameda County Public Health Department said in a press release a state lab used genomic sequencing to identify the five people infected with the omicron variant, each who were reported to be “mildly symptomatic.” They were among 12 people between the ages of 18 and 49 all linked to a November 27th wedding in Wisconsin.

One of those who attended the wedding had just returned from international travel.

All 12 of the individuals had been vaccinated and most had received boosters, the health department said. One person is a Berkeley resident and the remaining 11 are residents of Alameda County. None have been hospitalized.

Aside from the five cases confirmed to be the omicron variant, genomic sequencing has not yet been completed for the other seven.

The Alameda County and the City of Berkeley Public Health Departments are investigating these cases with the support of the California Department of Public Health. Close contacts are being notified and provided with isolation and quarantine guidance.