VGX-3400

VGX-3400 is a DNA vaccine developed as a prophylactic (preventative) immunization against avian influenza, specifically targeting the H5N1 subtype of the Influenza A virus. The vaccine consists of DNA plasmids encoding hemagglutinin (HA), neuraminidase (NA), and M2e-NP antigens from the H5N1 avian influenza virus. Its mechanism of action is to stimulate both humoral and cellular immune responses by inducing neutralizing antibodies and antigen-specific CD8+ T cell responses. Preclinical studies demonstrated potent immunogenicity in multiple animal models including mice, ferrets, pigs, and rhesus monkeys[7]. The vaccine was designed using SynCon technology to provide broad cross-reactive immunity against diverse influenza strains[7]. It was delivered intramuscularly with electroporation using the CELLECTRA device. Development reached Phase 1 clinical trials for prevention of avian influenza in humans but has not advanced further or received regulatory approval[3][4][5].