Gov. Charlie Baker announced more coronavirus vaccination sites this week, along with earlier eligibility for people 65 and over. He also pointed eligible residents to a state website that links to registration sites. But questions remain about the state’s rollout, which consistently has ranked in the lower half in the nation and which does not include a one-stop central registration system. Emergency room physician and state Rep. Jon Santiago, D-Suffolk, and Dorchester Reporter columnist and Codman Square Health Center founder Bill Walczak joined Jim Braude to discuss what needs to be fixed.