title: Heterologous flavivirus infection-enhancing antibodies in sera of Nigerians.
abstract: Human sera collected from Nigerians were examined for plaque reduction neutralizing and infection-enhancing antibodies against dengue 2, yellow fever, and West Nile viruses. Neutralization tests showed that 17 of 19 sera contained flavivirus neutralizing antibody; 11 were positive to all 3 viruses, 5 to dengue and yellow fever, and 1 to dengue virus only. Two sera had no detectable neutralizing antibody to any of the flaviviruses. Enhancement assays showed that 17 flavivirus neutralizing antibody-positive sera contained infection-enhancing antibodies to dengue 2, and 16 had antibody to yellow fever. Although 11 sera were positive for West Nile neutralizing antibody, 17 enhanced this virus. Heterologous infection-enhancing antibody titers were lower than the homologous ones. Broadly reacting sera and those with high neutralizing antibody titers produced the highest infection-enhancing antibody titers.
authors.affiliation: Department of Virology, College of Medicine, University of Ibadan, Nigeria.
authors.forename: A
authors.initials: A
authors.lastname: Fagbami
authors.forename: S B
authors.initials: SB
authors.lastname: Halstead
authors.forename: N
authors.initials: N
authors.lastname: Marchette
authors.forename: K
authors.initials: K
authors.lastname: Larsen
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis*; D003716:Dengue Virus / Q000276:immunology; D005312:Fetal Blood / Q000276:immunology; D005416:Flavivirus / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn; D009500:Neutralization Tests; D009549:Nigeria; D014036:Togaviridae Infections / Q000453:epidemiology / Q000276:immunology*; D014902:West Nile virus / Q000276:immunology; D015005:Yellow fever virus / Q000276:immunology
chemical_list: D000914:Antibodies, Viral