Prospects for control of emerging infectious diseases with plasmid DNA vaccines

Moss, Ronald B

Vaccination is an important component of a response to potential pandemics such as avian influenza. According to the World Health Organization (WHO), since November 2003, approximately 400 cases of human infection with highly pathogenic avian influenza A (H5N1) have been reported worldwide [36] . Pandemic (H5N1) influenza virus has evolved into at least 10 distinct clades or subclades. As noted earlier, the emergence of triple-reassortment swine influenza with limited cross reactivity antibody responses after vaccination with seasonal influenza vaccines suggests the need to rapidly produce new vaccines to this particular emerging virus [37] . The manufacturing time of conventional protein-based vaccines may be excessive, as they typically require growth in egg or cell cultures, which involve a relatively slow production time. DNA vaccines, in contrast, have estimated vaccine production times that can be months earlier, as only the DNA sequence is required and the manufacturing process is standard (Figure 3 ) [38] . DNA vaccines therefore have a unique advantage of large scale production for human use in a relatively streamlined period of time. In the case of potentially fatal emerging pathogens, reducing the production time of an effective vaccine may be critical in preventing spread of infection and death.