Immunization with a novel #RNA replicon #vaccine confers long-lasting #protection against #H5N1 avian #influenza virus in 24 #bird species
Abstract Highly pathogenic avian influenza viruses (HPAIV) of subtype H5N1 (clade 2.3.4.4b) have spread worldwide and caused the death of hundreds of millions of wild birds and domestic poultry . Moreover, spill over of H5N1 HPAIV from infected birds to more than 50 different mammalian species including humans has been recorded. While, licensed vaccines for protection of avian or mammalian species are not yet available, a few candidate vaccines are being trialled . Here, we report on the experimental vaccination of chickens and captive wild birds using a propagation-defective vesicular stomatitis virus ( VSV ), in which the essential envelope glycoprotein (G) protein gene was replaced by a modified hemagglutinin gene derived from a clade 2.3.4.4b H5N1 isolated in 2022 in the animal park of Bern, Switzerland. VSV∆G(H5mb) was produced on helper cells providing the VSV G protein in trans. Specific pathogen-free (SPF) chickens that were immunized twice via the intramuscular route with adju...