Four hospitals in Massachusetts received initial doses of the Pfizer COVID-19 vaccine on Monday and more than a dozen others expect to receive shipments this week. Secretary of Health and Human Services Marylou Sudders said during a Monday afternoon call with stakeholders that doses of the vaccine arrived at Boston Medical Center, Cape Cod Hospital, Falmouth Hospital and Signature Healthcare Brockton Hospital four hours ahead of schedule Monday. A spokesperson for Brockton Hospital confirmed receipt of the vaccine on Monday afternoon, but said it's not yet clear when the hospital will begin vaccinating workers. "We received 975 (doses) early this morning," Signature Healthcare said in a statement. "We were originally planning on vaccinations starting Monday, but we received the shipment earlier than anticipated. We are now in a re-planning phase where we are trying to get a few employees vaccinated this week."