The era of mass vaccinations is ending: Although these big sites were key to speeding up vaccinations after a rocky start in the winter, many are beginning to find themselves idle as the country’s daily vaccination rate falls from its mid-April peak. ... But with more than half of Americans still unvaccinated, the COVID-19 immunization campaign is far from over. It is now entering a new phase. Instead of in convention centers and arenas, shots will be distributed across a larger number of smaller sites: pharmacies, doctors’ offices, churches, mosques, factory parking lots, barbershops, bars, breweries, even individual homes.