Flagellin-HA vaccines protect ferrets and mice against H5N1 highly pathogenic avian influenza virus (HPAIV) infections

► Generated two formats of recombinant flagellin-HA vaccines targeting 3 H5N1 HPAIV. ► The vaccines protect ferrets against a lethal A/Vietnam/1203/04 challenge. ► The vaccines protect mice against a lethal A/Indonesia/5/05 challenge. ► Both R3.HA5 and R3.2xHA5 elicit robust long-lasting HAI antibody responses to HPAIV. ► The R3.2xHA5 format vaccines are more immunogenic than the R3.HA5 in mice.