Mass dog vaccination campaigns in an African city successfully interrupted rabies transmission for nine months during 2014, researchers report. They say their results show that currently available vaccines can halt the spread of rabies, provided that local communities are informed and engaged. Even though vaccines for dogs work well, more than 59,000 individuals die every year after contracting rabies from a canine. This problem is most severe in Africa and Asia, where some people cannot afford to inoculate their own pets and thus depend on free mass vaccination campaigns. Seeking a better understanding of the social and ecological factors determining whether mass vaccination will be successful, Jakob Zinsstag et al. analyzed rabies transmission in N'Djaména (the capital city of the African nation Chad) after two campaigns that occurred in 2012 and 2013. Both campaigns vaccinated roughly 71% of all dogs in the city during each year, and the scientists' analysis showed that no dogs became newly infected with rabies through November of 2014. What's more, the number of dog-to-human rabies transmissions was less than one per one million people during the nine months following the campaign. Although an earlier than anticipated jump in rabies transmission did occur in N'Djaména after the campaign, analysis of viral genomes indicated that the new cases came into the city from domestic dogs living in semi-urban areas surrounding the capital. The authors suggest that future dog rabies vaccination campaigns should be planned with wider coverage - including suburban and outlying areas - to halt transmission in urban centers.