title: Vaccine protection and reduced virus load from heterologous macaque-propagated SIV challenge.
abstract: The efficacy of vaccine protection afforded by live attenuated vaccines was tested by heterologous SIVtno8980 challenge following successful protection against homologous SIVmac32H challenge. Animals immunized with the attenuated SIVmacBK28 molecular clone were asymptomatic and virus isolation negative by quantitative virus isolation prior to challenge. Two groups of four animals previously immunized 5 years and 4 months (respectively) were challenged with 100 MID50 of SIVtno8980, as was a third group of four naive controls. All control animals that were challenged developed high levels of plasma antigenemia within 2 weeks of challenge and developed rapid Th/m cell loss whereas vaccinated animals did not. Quantitative virus isolation from peripheral blood mononuclear cells revealed that one of four animals in each group became virus isolation positive but that the virus load in the two vaccinated animals was markedly lower than in nonvaccinated controls. Studies are underway to determine the duration and immunological correlates of protection from AIDS.
authors.affiliation: Laboratory of Viral Pathogenesis, Biomedical Primate Research Center TNO, Rijswijk, The Netherlands.
authors.forename: J L
authors.initials: JL
authors.lastname: Heeney
authors.forename: L
authors.initials: L
authors.lastname: Holterman
authors.forename: P
authors.initials: P
authors.lastname: ten Haaft
authors.forename: R
authors.initials: R
authors.lastname: Dubbes
authors.forename: W
authors.initials: W
authors.lastname: Koornstra
authors.forename: V
authors.initials: V
authors.lastname: Teeuwsen
authors.forename: P
authors.initials: P
authors.lastname: Bourquin
authors.forename: S
authors.initials: S
authors.lastname: Norley
authors.forename: H
authors.initials: H
authors.lastname: Niphuis
mesh_terms: D000818:Animals; D007114:Immunization; D008253:Macaca mulatta; D009500:Neutralization Tests; D018449:SAIDS Vaccines / Q000276:immunology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000302:isolation & purification; D013045:Species Specificity; D013997:Time Factors; D014613:Vaccines, Attenuated / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D018449:SAIDS Vaccines; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic