NEUTRALIZATION SEROTYPES OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 FIELDISOLATES ARE NOT PREDICTED BY GENETIC SUBTYPE

Human immunodeficiency virus type 1 (HIV-1) primary isolates from four geographical locations in Thailand, Brazil, Rwanda, and Uganda, repre senting genetic subtypes A, B, C, D, and E, were examined for autologo us and heterologous neutralization by panels of human HIV+ polyclonal plasma. In independent linked experiments in three laboratories using diverse methodologies and common reagents, no defined pattern of genet ic subtype-specific neutralization was observed. Most plasma tested we re broadly cross-neutralizing across two or more genetic subtypes, alt hough the titer of neutralization varied across a wide range. We concl ude that the genetic subtypes of HIV-1 are not classical neutralizatio n serotypes.