Challenge of chimpanzees immunized with a recombinant canarypox-HIV-1 virus.
To evaluate the potential protective efficacy of a live recombinant human immunodeficiency virus type 1 (HIV-1) canarypox vaccine candidate, two chimpanzees were immunized five times with ALVAC-HIV-1 vCP250, a recombinant canarypox virus that expresses the HIV-1[IIIB(LAI)] gp120/TM, gag, and protease gene products. One month after the last booster inoculation, the animals were challenged by intravenous injection of cell-associated virus in the form of peripheral blood mononuclear cells from an HIV-1[IIIB(LAI)]-infected chimpanzee. One chimpanzee with a neutralizing antibody titer to HIV-1[IIIB(LAI)] of 128 at the time of challenge was protected, whereas both the second animal, with a neutralizing antibody titer of 32, and a naive control animal became infected. At 5 months after challenge, the protected chimpanzee and a third animal, previously immunized with various HIV-1[MN] antigens, were given a booster inoculation. The two animals were challenged intravenously 5 weeks later with twenty 50% tissue culture infectious doses of cell-free HIV-1[DH12], a heterologous subtype B isolate. Neither chimpanzee had neutralizing antibodies to HIV-1[DH12], and neither one was protected from infection with this isolate. The immune responses elicited by vaccination against HIV-1[IIIB(LAI)] or HIV-1[MN] did not, therefore, protect the animals from challenge with the heterologous cell-free HIV-1[DH12].
Girard
M
M
Institut Pasteur, Paris, France.
van der Ryst
E
E
Barré-Sinoussi
F
F
Nara
P
P
Tartaglia
J
J
Paoletti
E
E
Blondeau
C
C
Jennings
M
M
Verrier
F
F
Meignier
B
B
Fultz
P N
PN
D016915:AIDS Vaccines / Q000008:administration & dosage / Q000276:immunology*; D000818:Animals; D018150:Avipoxvirus / Q000235:genetics; D015483:HIV Antibodies / Q000096:biosynthesis; D015658:HIV Infections / Q000276:immunology / Q000517:prevention & control*; D015497:HIV-1 / Q000276:immunology; D007124:Immunoenzyme Techniques; D008297:Male; D009500:Neutralization Tests; D002679:Pan troglodytes; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D016915:AIDS Vaccines; C106488:ALVAC-HIV-1 vCP250; D015483:HIV Antibodies; D014614:Vaccines, Synthetic; D014765:Viral Vaccines