Candid1, a live-attenuated Junin virus vaccine strain, was developed during the early 1980s to control Argentine hemorrhagic fever, a severe and frequently fatal human disease. Six amino acid substitutions were found to be unique to this vaccine strain, and their role in virulence attenuation in mice was analyzed using a series of recombinant viruses. Our results indicate that Candid1 is attenuated in mice through a single amino acid substitution in the transmembrane domain of the G2 glycoprotein. This work provides insight into the molecular mechanisms of attenuation of the only arenavirus vaccine currently available.
Amino Acid Substitution Animals