Evaluation of different chemical adjuvants on an avian influenza H6 DNA vaccine in chickens

Abstract

This study assessed the ability of three adjuvants (aluminum hydroxide, Essai (microparticle) and Phema (nanoparticle)) to enhance the immune response of chickens to an H6N2 avian influenza DNA vaccine. No hemagglutination inhibition (HI) antibody was detected following two intramuscular immunizations with the adjuvanted and non-adjuvanted pCAG-HAk vaccine, which has previously been shown to induce moderate H6 HA antibody response in SPF chickens. Following virus challenge, neither the vaccinated group without adjuvant nor the Essai adjuvanted group showed a statistically significant reduction in virus shedding in oropharyngeal and cloacal swabs compared with the naïve control group. However, the aluminum hydroxide and Phema adjuvanted groups significantly reduced the frequency of virus shedding in oropharyngeal swabs, indicating that these adjuvants appeared to further enhance the vaccine potency. Aluminum hydroxide holds promise as an adjuvant for enhancing DNA-induced immune response in chickens owing to its low price and safety record.

Response to a DNA vaccine against the H5N1 virus depending on the chicken line and number of doses

“…Many DNA vaccine candidates for protecting chickens from avian influenza have been described [10,13,14], and one such vaccine has been licensed for use in the U.S. [15]. Protective DNA vaccine candidates were also designed and tested by our team [16][17][18][19][20].…”