PANOLA, Ala. — The dog-eared trailer that serves as the only convenience store within 20 miles of this blink-and-you-miss-it rural hamlet, population 144, is more than a place to stock up on life’s essentials. These days the store — or more precisely its proprietor, Dorothy Oliver — has become an unofficial logistics hub for African-American residents seeking the coronavirus vaccine.

Even as vaccine supplies in Alabama have become more plentiful, Ms. Oliver’s neighbors, many of them older and poor, lack the smartphones and internet service needed to book appointments. And if they manage to secure a slot, they may not have a way to get to distant vaccination sites.

Ms. Oliver helps her neighbors snag appointments online and matches them with those willing to make the 45-minute drive to Livingston, the seat of Sumter County and the nearest town offering inoculations. Nearly three-quarters of the residents of the county, which includes Panola, are African-American.  ...