Vaccination with attenuated simian immunodeficiency virus by DNA inoculation

Delivering attenuated lentivirus vaccines as proviral DNA would be simple and inexpensive. Inoculation of macaques with wild-type simian immunodeficiency virus strain mac239 (SIVmac239) DNA or SIVmac239 DNA containing a single deletion in the 3' nef-long terminal repeat overlap region (nef/LTR) led to sustained SIV infections and AIDS. Injection of SIVmac239 DNA containing identical deletions in both the 5' LTR and 3' nef/LTR resulted in attenuated SIV infections and substantial protection against subsequent mucosal SIVmac251 challenge.