Washington state announced on Wednesday that it was looking into several COVID-19 outbreaks linked to high school wrestling tournaments that have resulted in an estimated 80 to 90 cases.

The Washington State Department of Health said the cases were linked to four wrestling tournaments that all happened on Dec. 4 and included the participation of high schools from 13 Washington counties and one Oregon high school.

The state health department noted that the number of cases could still rise, but noted that at least three of those cases were related to omicron variant outbreaks. Officials said that the outbreaks occurred among both unvaccinated and vaccinated people. 

Health officials urged that anyone who had been at any of the wrestling matches, including athletes, spectators and coaches, should get tested and monitor their symptoms. People were advised to stay away from school or work if they noticed any symptoms or received a positive COVID-19 test.

“This outbreak serves as a clear reminder that COVID-19 continues to spread in our communities. The best protection against it is to get vaccinated, and then for those 16 years and older to get a booster shot as soon as they are eligible,” the health department said in its announcement.

The news comes as a dozen cases of the omicron variant have been reported in Washington state, according to the Seattle Times. Researchers from the University of Hong Kong’s LKS Faculty of Medicine indicated in a new study that the omicron variant infects humans 70 times faster than prior strains.

The research, which is still in peer review, suggests that the variant also may be less severe than previous ones. 

The study “showed that the Omicron infection in the lung is significantly lower than the original SARS-CoV-2, which may be an indicator of lower disease severity,” the university said in a statement regarding the research.