title: Immunization of newborn rhesus macaques with simian immunodeficiency virus (SIV) vaccines prolongs survival after oral challenge with virulent SIVmac251.
abstract: There is an urgent need for active immunization strategies that, if administered shortly after birth, could protect infants in developing countries from acquiring human immunodeficiency virus (HIV) infection through breast-feeding. Better knowledge of the immunogenic properties of vaccine candidates in infants and of the effect of maternal antibodies on vaccine efficacy will aid in the development of such a neonatal HIV vaccine. Simian immunodeficiency virus (SIV) infection of infant macaques is a useful animal model of pediatric HIV infection with which to address these questions. Groups of infant macaques were immunized at birth and 3 weeks of age with either modified vaccinia virus Ankara (MVA) expressing SIV Gag, Pol, and Env (MVA-SIVgpe) or live-attenuated SIVmac1A11. One MVA-SIVgpe-immunized group had maternally derived anti-SIV antibodies prior to immunization. Animals were challenged orally at 4 weeks of age with a genetically heterogeneous stock of virulent SIVmac251. Although all animals became infected, the immunized animals mounted better antiviral antibody responses, controlled virus levels more effectively, and had a longer disease-free survival than the unvaccinated infected monkeys. Maternal antibodies did not significantly reduce the efficacy of the MVA-SIVgpe vaccine. In conclusion, although the tested vaccines delayed the onset of AIDS, further studies are warranted to determine whether a vaccine that elicits stronger early immune responses at the time of virus exposure may be able to prevent viral infection or AIDS in infants.
authors.affiliation: California National Primate Research Center, University of California, Davis 95616, USA.
authors.forename: Koen K A
authors.initials: KK
authors.lastname: Van Rompay
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Greenier
authors.forename: Kelly Stefano
authors.initials: KS
authors.lastname: Cole
authors.forename: Patricia
authors.initials: P
authors.lastname: Earl
authors.forename: Bernard
authors.initials: B
authors.lastname: Moss
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Steckbeck
authors.forename: Bapi
authors.initials: B
authors.lastname: Pahar
authors.forename: Tracy
authors.initials: T
authors.lastname: Rourke
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Montelaro
authors.forename: Don R
authors.initials: DR
authors.lastname: Canfield
authors.forename: Ross P
authors.initials: RP
authors.lastname: Tarara
authors.forename: Christopher
authors.initials: C
authors.lastname: Miller
authors.forename: Michael B
authors.initials: MB
authors.lastname: McChesney
authors.forename: Marta L
authors.initials: ML
authors.lastname: Marthas
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood; D002772:Cholera Toxin / Q000276:immunology; D005434:Flow Cytometry; D007114:Immunization; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D007371:Interferon-gamma / Q000096:biosynthesis; D016131:Lymphocyte Subsets / Q000276:immunology; D008253:Macaca mulatta; D018449:SAIDS Vaccines / Q000276:immunology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000401:mortality / Q000517:prevention & control* / Q000635:transmission; D013745:Tetanus Toxoid / Q000276:immunology; D014613:Vaccines, Attenuated / Q000276:immunology; D014766:Viremia / Q000517:prevention & control
chemical_list: D000914:Antibodies, Viral; D018449:SAIDS Vaccines; D013745:Tetanus Toxoid; D014613:Vaccines, Attenuated; D007371:Interferon-gamma; D002772:Cholera Toxin