ABSTRACT Few countermeasures to treat Yellow Fever virus (YFV) infection are under development, because vaccines have helped to limit new infections. Unfortunately, vaccine hesitancy, supply deficits, and a paucity of therapeutic options have left individuals at risk. Here, we tested potent YFV-specific neutralizing monoclonal antibodies in rodents and non-human primates. We administered antibodies during acute pathogenic YFV infection and demonstrate that we can prevent severe disease and death. Given the severity of YFV-induced disease, our results show that these antibodies could be effective in saving lives and fill a much-needed void in managing Yellow Fever cases during outbreaks around the world. One Sentence Summary Therapeutic monoclonal antibodies prevent death from YFV infection.

Therapeutic neutralizing monoclonal antibody administration protects against lethal Yellow Fever infection