Mary Blackburn, 90, steered her wheelchair up to her kitchen table and readied for the shot. “Just a little pinch,” said Natalie O’Connor, a registered nurse and home care aide supervisor at Hartford HealthCare, injecting her with a dose of the Moderna COVID-19 vaccine at Blackburn’s Rocky Hill home on Friday. “That’s it? Wonderful!” Blackburn said with a wide smile. “I was expecting a bigger .