Development of a Nano-vaccine against a Wild Bird H6N2 Avian Influenza Virus

A DNA vaccine, pCAG-HAk, expressing the full-length haemagglutinin (HA) gene of avian influenza A/Eurasian coot/Western Australia/2727/1979 (H6N2) virus, together with a Kozak sequence, in a pCAGGS vector was formulated with a novel nanoparticle, Phema. Two intramuscular immunizations of layer chickens at 3-week intervals with different doses of a nano-vaccine as well as 100μg pCAG-HAk failed to induce detectable haemagglutination-inhibition (HI) antibody. Following virus challenge, the pCAG-HAk vaccinated group did not show a statistically significant difference in frequency of virus shedding in both oropharyngeal and cloacal swabs from the naive control group. However, in comparison with the naive control group, the 100μg nano-vaccine group did significantly reduce virus shedding from the oropharynx. Despite lack of a dose-sparing effect from the nano-vaccine, there was a dose-response effect. This pilot study indicated that Phema used as an adjuvant augmented the immune response induced by the pCAG-HAk construct.