Comparison of Dengue-2 and Dengue-3 Virus Strains by Neutralization Tests and Identification of a Subtype of Dengue-3

Abstract
Strains of dengue-2 and dengue-3 viruses of diverse geographic origins including southeast Asia, the Caribbean region, Africa, and Tahiti were compared by plaque-reduction neutralization tests with hyperimmune-mouse ascitic fluids and human convalescent sera. The dengue-2 strains all appeared similar. The dengue-3 strains from the Caribbean and from Tahiti were similar to each other and differed significantly from the southeast Asian strains. A subtype of dengue-3 virus was defined.