The invention relates to HIV chimeric gene formed by the union of fragments of different genes of said virus, wherein said fragments contains epitopes for cytotoxic T cells (CTL) or HIV-1 auxiliary T cells, which are presented by a wide range of antigens of type Major Histocompatibility Complex (HLA-I). Recombinant poxviruses are obtained from said genes, which are useful for prophylactic and therapeutic vaccination against HIV/AIDS infections, are capable of generating a protective immune cell response in vaccinated laboratory animals and are recognized by the CTL lymphocytes of HIV/AIDS patients.