ETIDIOH - NEW

Abstract In 2023, Finland faced an outbreak of highly pathogenic avian influenza caused by clade 2.3.4.4b A(H5N1) viruses , which spread from wild birds to fur farms . Vaccinations of individuals at-risk , such as fur and poultry farm workers , veterinarians, and laboratory workers , began in June 2024 using the MF59-adjuvanted inactivated (H5N8) vaccine manufactured by Seqirus (based on clade 2.3.4.4b A/Astrakhan/3212/2020). We investigated antibody responses following a two-dose vaccination regimen in 39 subjects. Vaccination induced comparable levels of functional antibodies both against the vaccine virus and two clade 2.3.4.4b viruses, either associated with outbreaks in fur animals in Finland or cattle in the United States . Upon two doses of the vaccine for previously unvaccinated people, the seroprotection rate against the vaccine virus was 83 % (95 % CI 70-97 %, titer ≥20) and 97 % (95 % CI 90-100 %, titer ≥40) using microneutralization or hemagglutinin inhibition assays , resp...

 A wild Eurasian Jackdaw in Lounais-Suomen aluehallintovirasto Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6229 _____

Abstract Highly pathogenic avian influenza (HPAI) H5N1 is known for its virulence and zoonotic potential, infecting birds and mammals , thus raising public health concerns. Since 2021 its spread among birds has led to cross-species transmission causing epizootics among mammals, eventually impacting fur animal farms in Finland in 2023. To analyze the infectivity of the Finnish H5N1 isolates in human cells , representatives of diverse H5N1 isolates were selected based on the genetic differences, host animal species, and the year of occurrence. The infection kinetics of the selected H5N1 isolates from wild pheasant and fox , and fur animals blue fox and white mink were examined in human monocyte-derived dendritic cells (moDCs) with H5N1 human isolate as a control. Although the isolate from pheasant (a wild bird) showed weakly reduced replication and viral protein expression in human cells compared to mammalian isolates, no discernible differences in virus replication in moDCs was observed...