Table II. Disadvantages of DNA vaccines.

Disadvantages of DNA vaccines	References
Limited to protein immunogens (not useful for non-protein based antigens such as bacterial polysaccharides). Certain vaccines, such as those for pneumococcal and meningococcal infections, use protective polysaccharide antigens	23
Inducing antibody production against DNA	25
May induce immunologic tolerance by antigens expressed inside host body	25
DNA vaccines may have a relatively poor immunogenicity	31
Atypical processing of bacterial and parasite proteins	28
Insertion of foreign DNA into the host genome may cause the cell to become cancerous	25