The number of COVID-19 cases is up across the country and COVID-19 hospitalizations have been increasing since late summer.

In Massachusetts, there were 2,700 new confirmed cases reported last week and 116 hospitalizations. The newest COVID-19 booster vaccine is now available after approval from the FDA and CDC.

Dr. Richard Ellison, a specialist for infectious diseases at UMass Memorial Medical Center, said they’re tracking two new COVID-19 variants that emerged towards the end of the summer.

“It’s obvious that these are very easily spread,” Ellison said. “We saw pretty much a doubling of the number of health care workers in our system here at UMass coming down with COVID, and at the end of August, early September, it was a five-fold increase over June.”

Ellison said there is the potential for cases to continue to rise as people spend more time inside during the fall and winter.

Watch Ellison’s full conversation with Spectrum News 1 in the video above.