Immunization of newborn rhesus macaques with simian immunodeficiency virus (SIV) vaccines prolongs survival after oral challenge with virulent SIVmac251.
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.
Van Rompay
Koen K A
KK
California National Primate Research Center, University of California, Davis 95616, USA.
Greenier
Jennifer L
JL
Cole
Kelly Stefano
KS
Earl
Patricia
P
Moss
Bernard
B
Steckbeck
Jonathan D
JD
Pahar
Bapi
B
Rourke
Tracy
T
Montelaro
Ronald C
RC
Canfield
Don R
DR
Tarara
Ross P
RP
Miller
Christopher
C
McChesney
Michael B
MB
Marthas
Marta L
ML
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
D000914:Antibodies, Viral; D018449:SAIDS Vaccines; D013745:Tetanus Toxoid; D014613:Vaccines, Attenuated; D007371:Interferon-gamma; D002772:Cholera Toxin