ETIDIOH - NEW

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...

ABSTRACT The current situation with H5N1 highly pathogenic avian influenza virus (HPAI) is causing a worldwide concern due to multiple outbreaks in wild birds, poultry, and mammals. Moreover, multiple zoonotic infections in humans have been reported. Importantly, HPAI H5N1 viruses with genetic markers of adaptation to mammals have been detected. Together with HPAI H5N1, avian influenza viruses H7N9 (high and low pathogenic) stand out due to their high mortality rates in humans . This raises the question of how prepared we are serologically and whether seasonal vaccines are capable of inducing protective immunity against these influenza subtypes. An observational study was conducted in which sera from people born between years 1925–1967, 1968–1977, and 1978–1997 were collected before or after 28 days or 6 months post-vaccination with an inactivated seasonal influenza vaccine. Then, hemagglutination inhibition, viral neutralization, and immunoassays were performed to assess the basal pro...

Abstract The conserved influenza hemagglutinin stem , which is a target of cross-neutralizing antibodies , is now used in vaccine strategies focused on protecting against influenza pandemics . Antibody responses to group 1 stem have been extensively characterized, but little is known about group 2 . Here, we characterized the stem-specific repertoire of individuals vaccinated with one of three group 2 influenza subtypes ( H3, H7, or H10 ). Epitope mapping revealed two epitope supersites on the group 2 stem. Antibodies targeting the central epitope were broadly cross-reactive , whereas antibodies targeting the lower epitope had narrower breadth but higher potency against H3 subtypes . The ratio of B cells targeting each of the supersites varied with the vaccine subtype, leading to differences in the cross-reactivity of the B cell response. Our findings suggest that vaccine strategies targeting both group 2 stem epitopes would be complementary, eliciting broader and more potent protectio...

Abstract Infectious bursal disease virus (IBDV) is endemic worldwide and causes immunosuppression in chickens . We hypothesized that a previous history of IBDV in chickens would render them more susceptible to infection by influenza A viruses (IAVs) from aquatic waterfowl reservoirs . To model this, we inoculated 14 day old specific pathogen free (SPF) chickens with a low pathogenicity avian influenza (LPAI) virus strain from a mallard ( A/Mallard/Alberta/156/01 (H3N8) ) and compared replication and shedding between immunocompetent chickens and chickens that had immune dysregulation due to a prior IBDV infection with strain F52/70 (genogroup A1B1) at 2 days of age. The mallard IAV strain replicated in the upper respiratory tract of the chickens , and virus was shed from the oropharyngeal cavity , but there was no shedding from the cloaca , and no transmission to sentinel chickens . Replication of the mallard IAV in the chicken host was associated with amino acid substitutions in the po...