Local public health experts had mixed reactions to the federal government’s move Tuesday to recommend a “pause” of the use of Johnson & Johnson’s one-shot COVID-19 vaccine after a half dozen women experienced a rare but severe type of blood-clotting, even if cases were less than one in a million. “Glad to see safety prioritized, even for incredibly rare events,” MassHealth medical director Lakshman Swamy tweeted, adding that the vaccine “still seems overwhelmingly safe” and effective against preventing hospitalization or death due to COVID-19. “Many of us are caring for young people with severe COVID and see the benefits in front of us,” Swamy wrote. “If available, I would still get this shot.”