HETEROLOGOUS HIV-2 CHALLENGE OF RHESUS-MONKEYS IMMUNIZED WITH RECOMBINANT VACCINIA VIRUSES AND PURIFIED RECOMBINANT HIV-2 PROTEINS

In an attempt to analyse the role of anti-envelope immunity in the pro tection of rhesus monkeys against an HIV-2 intravenous challenge, rhes us macaques were immunized twice with recombinant HIV-2 ROD vaccinia v iruses (10(8) p.f.u. each) at days 0 and 30,followed by booster inject ions of purified HIV-2 proteins at months 8, 9, 15 and 27. One group o f five macaques was immunized with the Gag, Pol, Vif and Nef antigens, whereas a second group received the same antigens with the addition o f HIV-2 Env protein. Eight months after the last boost, the animals we re challenged by intravenous injection of 100 AID(50) of a monkey PBMC -grown stock of HIV-2 SBL. None of the animals was protected in spite of high humoral immune responses on day, of challenge as determined by ELISA and Western Blot assays.