(CBS Detroit) — Michigan health officials announced Thursday that the state’s first case of the omicron variant has been identified in a Kent County resident.

Officials say the initial detection of the COVID cases was reported on Dec. 3 to the Michigan Disease Surveillance System. On Dec. 9, the Michigan Department of Health and Human Services (MDHHS) was notified by the Centers for Disease Control and Prevention it was the omicron variant following genetic sequencing.

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Vaccine records indicate the adult was fully vaccinated but had not received a booster shot.

“We are concerned, although not surprised, about the discovery of the Omicron variant in Michigan,” said MDHHS Director Elizabeth Hertel in a news release.

“We continue to urge Michiganders ages 5 and up to get vaccinated and continue participating in measures we know slow the spread of the virus by wearing well-fitting masks properly, socially distancing, avoiding crowds, washing their hands often and testing for COVID-19. Vaccines are our best defense against the virus and how we can manage the spread of COVID-19.”

MDHHS says it is coordinating with the Kent County Health Department on investigating the COVID case.

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Public health follow-up will include an assessment of the potential for out-of-state exposure, compliance with isolation guidance and outreach to close contacts.

“The identification of the Omicron variant is not unexpected,” says Dr. Adam London, Kent County Health Department director. “We are fortunate that we have effective, safe and available vaccines that can protect us from this illness. We continue to urge people to get their vaccine and to get their boosters as soon as they are eligible.”

On Nov. 30, the omicron variant, B.1.1.529, was classified as a variant of concern by the CDC. It was first detected in South Africa. The first case in the U.S. was confirmed on Dec. 1.

More than 20 states have confirmed omicron detections.

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