GRAND RAPIDS, Mich. (WOOD) — Health officials say Michigan’s first confirmed case of the omicron variant of coronavirus has been detected in a person in Kent County.

The person who tested positive is an adult who was fully vaccinated against COVID-19 but had not received a booster dose, the Michigan Department of Health and Human Service said Thursday.

Pfizer says a booster of its vaccine will help protect against omicron. Those boosters were opened up to people as young as 16 on Thursday.

“The identification of the Omicron variant is not unexpected,” Kent County Health Department Health Officer Adam London said in a statement released by MDHHS. “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.”

Omicron is considered a variant of concern because it may be more contagious than the initial strain of the virus. The good news is that so far, omicron doesn’t appear to cause more serious cases of COVID-19 — though experts have cautioned they are still investigating.

The Kent County person tested positive for the virus on Dec. 3 and genetic sequencing subsequently confirmed it was omicron. Not every positive test is sequenced. MDHHS is investigating the case and reaching out to people who may be close contacts.

More than 20 other states have already confirmed omicron cases, but delta is still the United States’ biggest problem and it is the variant driving the current surge.

Michigan health officials reminded people that the vaccines are still the best way to protect yourself from COVID-19. While breakthrough cases exist, they are generally more mild than cases in those who are not vaccinated.

“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,” MDHHS Director Elizabeth Hertel said. “Vaccines are our best defense against the virus and how we can manage the spread of COVID-19.”

The majority of people currently hospitalized with COVID-19 in Michigan have not been fully vaccinated. The state says people who have not been vaccinated are more than four times more likely to catch coronavirus and more than nine times more likely to die of it.

“We have tools that prevent the spread of COVID-19, including Omicron. However, we continue to see that those not utilizing these tools, including vaccines, are disproportionately affected by this virus,” the state’s chief medical executive Dr. Natasha Bagdasarian said. “The data is clear that these vaccines are extremely safe and effective, and the side effects of COVID-19 are much worse than receiving a vaccine. I emphasize the importance of not waiting to get vaccinated. Now is the time.”