Gov. Baker: State ready to work single-dose COVID-19 vaccine into mix, arms By Chris Lisinski BOSTON — Gov. Charlie Baker said Monday that he is optimistic the Johnson & Johnson vaccine approved for emergency use over the weekend will accelerate the effort to get more Massachusetts residents protected against COVID-19 — even if states will face a gradual ramp-up in delivery. While the state forges ahead to ease COVID-19 restrictions on businesses — despite warnings against doing so from federal health officials — Baker said Monday that he is hopeful J&J doses will "dramatically boost" the work to get shots in arms. Unlike the two-dose Pfizer and Moderna options already in public use, the Johnson & Johnson vaccine to which the U.S. Food and Drug Administration awarded emergency use authorization Saturday requires just a single shot with simpler transportation and storage requirements.