A multistep procedure for the chemical inactivation of human immunodeficiency virus for use as an experimental vaccine.

The kinetics of inactivation of four different strains of HIV-1 (RF, MN, SF2 and IIIB) by beta-propiolactone (BPL) and binary ethylenimine (BEI) were studied under various conditions. The conditions that would be required for the reduction of virus infectivity by at least 10(20) TCID50 ml-1 were estimated on the basis of the experimental rates of inactivation obtained. A multiple step procedure including treatment with 0.2% BPL, 0.05% sodium cholate, 10 mM BEI and 0.02% formaldehyde was designed to inactivate HIV-1 for use as an experimental vaccine. Complete inactivation of virus infectivity was confirmed by prolonged cell culture. The experimental vaccine preparation was analysed for the presence of HIV-1 proviral DNA utilizing the polymerase chain reaction. After treatment with both BPL and BEI proviral DNA was detected in one of four samples using primers encoding a 244 bp segment of the pol region of the viral genome. Proviral DNA could not be detected in any of the four samples using primers encoding segments of > 400 bp in the gag and reverse transcriptase region.