Background
Although the importance of DNA vaccines, especially as a priming immunization has been well established in numerous HIV vaccine studies, the immunogenicity of DNA vaccines is generally moderate. Novel adjuvant is in urgent need for improving the immunogenicity of DNA vaccine. Mycobacterium bovis bacillus Calmette-Guérin (BCG) cell-wall skeleton and nuclear acid which can activate at least five kinds of TLRs (TLR1, TLR2, TLR4, TLR6 and TLR9).