Maryland state health officials have confirmed the first three cases of the COVID-19 Omicron variant (B.1.1.529) in the D.C. area. Maryland Gov. Larry Hogan made the announcement today.

All three cases are reported to involve Maryland residents from the Baltimore region, according to Hogan, though none of the individuals have been hospitalized. The news comes just a week after the World Health Organization designated Omicron as a variant of concern.

“Thanks to our aggressive surveillance system, we have quickly identified the first cases of the Omicron variant in Maryland,” Hogan said in a statement. “This is a rapidly evolving situation, and we will continue to keep Marylanders updated as new information becomes available.”

The presence of the Omicron variant was confirmed through the Maryland Department of Health Public Health Laboratory and other partners. According to the report, two of the individual cases came from the same household and included one vaccinated person who had recently traveled to South Africa (where the Omicron variant was first identified). The third case is unrelated and is thought to involve one vaccinated person with no recent travel history.

Hogan said that contact tracing on the three patients is underway, and encouraged Marylanders to get vaccinated and receive booster shots, as well as to get tested for COVID-19 after travel.

The Omicron coronavirus variant has been reported in at least five U.S. states, though little is known about it, including whether the variant is more transmissible or severe than others. According to the WHO, studies are underway to determine how effective vaccines are against this new variant.

In recent weeks, various local jurisdictions have changed their policies on masking to prevent the spread of coronavirus. In Maryland, Montgomery County recently reinstated its indoor mask mandate, citing seven consecutive days of “substantial” COVID spread, and Prince George’s County officials voted to extend its mask mandate through January. Some Virginia counties, including Arlington and Fairfax, require masks in some settings, such as government buildings. D.C. Mayor Muriel Bowser, meanwhile, lifted the District’s indoor mask mandate in late November (though on Thursday, DC Health handed down a strong recommendation to keep up mask-wearing).

Earlier this week, the Maryland Department of Health shared they would be working to increase lab capacity in order to ramp up state testing. The move stemmed from a $2.2 million emergency appropriation for reagents and other equipment for lab testing. The state’s Board of Public Works said that information gathered from the tests would be used for “patient management as well as to target and stop the spread of the virus.”

As of Friday, Maryland’s seven-day average of new reported COVID cases per 100,000 residents is at 24 — a 55% increase from the previous week, according to the Washington Post coronavirus tracker.

This post has been updated with additional information about COVID-19 in the D.C. area, and the region’s mask mandates.