The virus that causes COVID-19 as seen through a transmission electron microscope. Photo courtesy of the National Institute of Allergy and Infectious Diseases

A woman in her 20s who had traveled out of state is the first known case of the Omicron variant of the coronavirus detected in Massachusetts, the state Department of Public Health announced Saturday.

Genetic sequencing confirmed the variant, officials said. The unidentified woman – a resident of Middlesex County – is fully vaccinated, has experienced mild disease, and did not require hospitalization according to the state health department.

Much remains unknown about Omicron, including whether it is more contagious, as some health authorities suspect, whether it can thwart vaccines and whether it makes people as sick as the original strain.

News of the arrival of the Omicron variant comes as the state has experienced a rise in COVID-19 cases.

Gov. Charlie Baker last week announced an emergency order requiring any hospital or hospital system facing limited patient capacity to reduce non-essential, non-urgent scheduled procedures.

As of Friday, there were more than 1,000 people hospitalized with COVID-19 in Massachusetts and more than 190 in intensive care units.

More than 19,000 people in Massachusetts have died from COVID-19 since the start of the pandemic.

State health officials urged residents to take the steps already available to protect themselves against COVID-19. Including getting vaccinated and receiving a booster shot when they are eligible.

The vaccine is free, and no ID or insurance is required for vaccination. A list of vaccination locations is available at vaxfinder.mass.gov. There are over 1,000 locations across the Commonwealth to get vaccinated or receive a booster.