The numbers are good â mostly. Across the state, the seven-day rolling average of new cases has remained below 100 since the middle of June, well below the levels of last summer. In Berkshire County, infection numbers have fluctuated around the same level as last summer, with an average of one to three new cases each day. But the good news comes as the Delta variant continues to spread, including in Massachusetts. According to estimates from the Centers for Disease Control and Prevention, as of early July, the highly transmissible variant accounted for one in every three COVID-19 cases in the Northeast.