The outbreak of clade 2.3.4.4b H5 highly pathogenic avian influenza (HPAI) in North America that started in 2021 has increased interest in applying vaccination as a strategy to help control and prevent the disease in poultry. Two commercially available vaccines based on the recombinant herpes virus of turkeys (rHVT) vector were tested against a recent North American clade 2.3.4.4b H5 HPAI virus isolate: A/turkey/Indiana/22-003707-003/2022 H5N1 in specific pathogen free white leghorn (WL) chickens and commercial broiler chickens. One rHVT-H5 vaccine encodes a hemagglutinin (HA) gene designed by the computationally optimized broadly reactive antigen method (COBRA-HVT vaccine). The other encodes an HA gene of a clade 2.2 virus (2.2-HVT vaccine). There was 100% survival of both chicken types COBRA-HVT vaccinated groups and in the 2.2-HVT vaccinated groups there was 94.8% and 90% survival of the WL and broilers respectively. Compared to the 2.2-HVT vaccinated groups, WL in the COBRA-HVT vaccinated group shed significantly lower mean viral titers by the cloacal route and broilers shed significantly lower titers by the oropharyngeal route than broilers. Virus titers detected in oral and cloacal swabs were otherwise similar among both vaccine groups and chicken types. To assess antibody-based tests to identify birds that have been infected after vaccination (DIVA-VI), sera collected after the challenge were tested with enzyme-linked lectin assay-neuraminidase inhibition (ELLA-NI) for N1 neuraminidase antibody detection and by commercial ELISA for detection of antibodies to the NP protein. As early as 7 days post challenge (DPC) 100% of the chickens were positive by ELLA-NI. ELISA was less sensitive with a maximum of 75% positive at 10DPC in broilers vaccinated with 2.2-HVT. Both vaccines provided protection from challenge to both types of chickens and ELLA-NI was sensitive at identifying antibodies to the challenge virus therefore should be evaluated further for DIVA-VI.

In 2020, the Y280-lineage H9N2 low-pathogenic avian influenza (LPAI) virus was introduced in South Korea for the first time. Current vaccines are focused on the control of Y439-like viruses; however, there are continuous reports of decrease in egg production and secondary infections caused by Y280-lineage H9N2 LPAI infection in chickens. Therefore, there is an urgent need to develop effective novel vaccines against Y280-lineage H9N2 LPAI. Most commercialized avian influenza vaccines are oil-adjuvanted inactivated vaccines, which are labour-intensive to administer and require higher dosage. In this study, rK148/Y280-HA, a novel recombinant Newcastle disease virus (NDV) vectored vaccine against Y280 lineage H9N2 LPAI was developed and evaluated using two mass-applicable administration methods, spray vaccination and drinking water vaccination. Regardless of low serum antibody haemagglutination inhibition titres against NDV and Y280 lineage H9N2 LPAI after applying the rK148/Y280-HA vaccine, vaccination with both administration methods protected chickens against virulent NDV and Y280-lineage H9N2 LPAIV after the challenge. Taken together, these results indicate that the rK148/Y280 vaccine can be administered using facile mass-application methods to provide protection against the Y280-lineage LPAI.

In the present study, dermal and inhalation exposure of agricultural workers to insecticide, flubendiamide were determined during pesticide mixing/loading, and hand-held sprayer application in Kimchi cabbage fields, and the potential health risk was assessed. Dermal exposure amount during mixing/loading was 0.8 mg, whereas there was no inhalation exposure (0.0 µg) during similar procedures. Among several different body parts, the hands were the most prominent exposure area (84.5%), followed by the chest and stomach (10.1%). The protective role of PPE (personal protective equipment) during application was determined by comparative experiments with- and without-PPE. The dermal and inhalation exposure with PPE was 3.7 mg and 12.0 µg, respectively. The Forearms (29.6%) and pelvis (18.7%) showed the highest pesticide exposure, followed by the chest and stomach (18.4%). However, the exposure amount of without-PPE was 47.7 mg, and 22.9 µg, respectively, where shins were the most prominent exposure area (83.0%). For the risk assessment of the mixing/loading and application, the AOEL (acceptable operator exposure level) of flubendiamide was used as the reference dose to calculate that the RI (risk index) was much lower than 1 (mixing/loading:0.0, application with PPE:0.2), indicating that agricultural workers are at low risk of exposure to flubendiamide. On the other hand, in the case of an application without PPE, RI is higher than 1 (9.8), suggesting that it can be at risk.

A thermostable, safe, and effective NDV GVII recombinant vaccine was generated.Fusion gene replacement with GVII did not affect GI K148/08 virus thermostability.Strain rK148/GVII-F provided adequate protection against a lethal NDV challenge.Oropharyngeal shedding was significantly reduced on post-challenge days 5 and 7.