Sites at the Reggie Lewis Center in Roxbury and Fenway Park began administering coronavirus vaccines this week. Currently, the Reggie Lewis Center is only serving those who live or work in Boston, but will convert to vaccinating all eligible Massachusetts residents by the end of the month, according to Gov. Charlie Baker. Including Gillette Stadium in Foxborough, the Double Tree Hilton Hotel in Danvers (which opened Wednesday) and the Eastfield Mall in Springfield, there are five mass vaccination sites throughout the state. Baker promises two more mega sites will be open soon. Baker said these mass vaccination sites are the most efficient, and open up new appointments every Thursday. However, there are many smaller sites taking appointments as well; those inside grocery stores, schools, municipal buildings, churches, community health centeres and physician offices.