“You have to think: Let’s look geographically — where do we have low vaccination rates?” she said. “And then drill down within that: Who are the people and what’s going to resonate with them?” That might range from a smaller site near a community hub where people can easily walk up to receive a shot, or a van bringing vaccinations to an apartment complex. Such approaches are already being deployed in cities like Baltimore, which recently launched a pop-up clinic at a community college. The idea is to use door-knocking campaigns and social media advertisements to spread the word in nearby neighborhoods before each clinic. In Baton Rouge, Louisiana, officials are planning an outreach event outside a popular nightclub. In Chicago, youth ambassadors with Increase the Peace, an anti-violence initiative, have also started sharing information about the shots.