Pharmaceutical compositions which comprise HIV Pol DNA vaccines are disclosed, along with the production and use of these DNA vaccines. The pol-based DNA vaccines of the invention are administered directly introduced into living vertebrate tissue, preferably humans, and preferably express inactivated versions of the HIV Pol protein devoid of protease, reverse transcriptase activity, RNase H activity and integrase activity, inducing a cellular immune response which specifically recognizes human immunodeficiency virus-1 (HIV-1). The DNA molecules which comprise the open reading frame of these DNA vaccines are synthetic DNA molecules encoding codon optimized HIV-1 Pol and codon optimized inactive derivatives of optimized HIV-1 Pol, including DNA molecules which encode inactive Pol proteins which comprise an amino terminal leader peptide.