TITRATION OF A VACCINE STOCK PREPARATION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE 1(SF2) IN CULTURED LYMPHOCYTES AND IN CHIMPANZEES

A large stock preparation of the HIV-1(SF2) isolate has been derived a fter serial passage in human peripheral blood mononuclear cells (PBMCs ). This viral stock has a titer of 10(4.9) TCID50 in human PBMCs and 1 0(4.2) TCID50 in chimpanzee PBMCs, Bg inoculation into animals the 50% chimpanzee infectious dose titer was found to be about 10(2.3). Virus isolation from animals was achieved on most occasions within 1-4 week s after inoculation and then became transient, Viral RNA and DNA PCR a nalyses confirmed the virus infection of the chimpanzees, Anti-HIV ant ibody levels in the inoculated animals ranged from 1:400 to 1:6400 as measured by ELISA, About 680 vials of this stock preparation, frozen a t -190 degrees C, are available for future studies of vaccines and ant iviral therapies.