Human immunoglobulin specificity after group B arbovirus infections.

Sera obtained during a dengue-2 epidemic from individuals with primary or secondary group B arbovirus infections contained cross-reactive antibody against several viruses in this group. Hemagglutination-inhibition antibody titers of the immunoglobulin M fractions from these sera revealed a rise in antibody specific for dengue-2. The acute and convalescent sera in over half of the secondary infection group also had low-level unchanging immunoglobulin M antibody titers to yellow fever which implicated yellow fever immunization as the primary infection.