Rising coronavirus cases on Martha’s Vineyard have some businesses taking extra precautions ahead of a busy stretch of late-summer festivals. Covid-19 cases have shot back up on Martha’s Vineyard, with health agents reporting 48 new positive tests during the first week in August, including three case clusters Earlier this week, as word of Saturday’s shindig circulated on the island, many expressed surprise — not because director Steven Spielberg and singer Usher were rumored to be attending, but because COVID-19 cases are on the increase in Massachusetts. Even among fans of the former president, of which there are many on Martha’s...