Recombinants containing and expressing lentivirus, retrovirus or immunodeficiency virus DNA and methods for making and using the same are disclosed and claimed. In an exemplified embodiment, attenuated recombinant viruses containing DNA encoding a feline immunodeficiency virus epitope such as an antigen, as well as methods and compositions employing the viruses, expression products therefrom, and antibodies generated from the viruses or expression products, are disclosed and claimed. The recombinants can be NYVAC or ALVAC recombinants. The DNA can encode at least one of: Env, Gag, Pol, or combinations thereof such as Gag and Pol or protease or Env, Gag and Pol or protease. The recombinants and gene products therefrom and antibodies generated by them have several preventive, therapeutic and diagnostic uses. DNA from the recombinants are useful as probes or, for generating PCR primers or for immunization. The immunogenicity and protective efficacy of immunization protocols involving ALVAC-FIV and priming with a recombinant canarypox virus ALVAC-FIV vaccine followed by a booster immunization with inactivated FIV-infected celled vaccine (ICV) was evaluated against FIV challenge in cats and the protocol was shown to effectively induce FIV-specific protective immune responses. Further, it was found that immunized cats were fully protected from an initial challenge with a slightly heterologous FIV strain (50CID.sub.50) and were partially protected from a second challenge with a distinctly heterologous FIV strain (75CID.sub.50) given eight months after the initial challenge without any intervening booster.