How the racial gap was narrowed — after months of disappointing turnout and limited access — is a testament to decisions made in many states to send familiar faces to knock on doors and dispel myths about the vaccines’ effectiveness, provide internet access to make appointments and offer transportation to vaccine sites.

In North Carolina, which requires vaccine providers to collect race and ethnicity data, hospital systems and community groups conducted door-to-door canvassing and hosted pop-up clinics at a theme park, a bus station and churches. Over the summer, the African American share of the vaccinated population began to more closely mirror the African American share of the general population.

In Mississippi, which has one of the country’s worst vaccination rates and began similar endeavors, 38 percent of people who have started the vaccine process are Black, a share that is roughly equal to the Black share of Mississippi’s population.

And in Alabama, public awareness campaigns and rides to vaccination sites helped transform dismal inoculation rates. A store owner and county commissioner in Panola, a tiny rural town near the Mississippi border, led the effort to vaccinate nearly all of her majority Black community.