An Inactivated Cell-Culture Vaccine against Yellow Fever

The live attenuated yellow fever vaccine is highly efficacious but is associated with rare, serious side effects. In this phase 1 study of healthy adults, two doses of an inactivated yellow fever vaccine elicited neutralizing antibodies against yellow fever virus in nearly all subjects Yellow fever, a lethal, mosquito-borne flavivirus disease, occurs in tropical South America and Africa. A live attenuated vaccine (17D) developed in 1936 is widely used, with approximately 20 million doses distributed annually. Although remarkably immunogenic, the 17D vaccine may cause serious viscerotropic and neurotropic adverse events and anaphylaxis. Viscerotropic disease is a fulminant 17D virus infection of the liver and visceral organs resembling naturally acquired yellow fever. Neurotropic disease typically follows invasion of the brain by the replicating vaccine virus. Fifty-nine cases of viscerotropic disease (38 of which [64%] were fatal) have been reported since 1973. 1 In the United States . . .