Frustration is building over the pace of COVID-19 vaccinations at long-term care sites, where some homes still await shots while fending off a virus that can devastate their residents. The major drugstore chains tasked with giving shots in these places are far along in vaccinating nursing home residents and staff. But some other group residences won’t receive first doses until mid-February or later. CVS and Walgreens say they are proceeding on schedule with their massive vaccination push. But resident advocates and experts are anxious about delays in delivering vaccines that have been available for more than a month.