Pandemic preparedness: Newcastle disease virus-vectored vaccine against HPAI H5

Over the past decade, highly pathogenic avian influenza virus strains from Eurasia have increasingly spread to North America, causing severe outbreaks in poultry and posing a threat to humans. A new influenza H5N1 virus reached Eastern Canada in late 2021 via migratory birds. This virus has adapted to local wildlife, becoming endemic in wild birds in North America. It has also been shown to infect various mammals, including ruminants like goats and dairy cows, where it accumulates at high concentration in udder and milk. This broad host range increases the risk of human infection. As these viruses become more common in farm animals, there is growing support for livestock vaccination, which can improve animal welfare and protect human health by reducing virus spread. Our proposal aims to test a new vaccine using a non-virulent Newcastle disease virus (NDV) to deliver a component of the influenza virus (the H5 gene) to promote antibody development in chickens, ducks, and sheep (as a model for dairy cows). This vaccine can be administered through mucosal routes, like sprays or drinking water, making mass vaccination easier. We plan to develop three NDV vaccine candidates expressing different versions of the H5 gene. We will first test these candidates for effectiveness in hamsters and chickens. The best candidate will then be tested in chickens and ducks to see if it can protect against H5N1 infection and transmission. Lastly, we will test the vaccine's effectiveness in lactating sheep, specifically focusing on antibody release in milk. This research will help Canada prepare for H5N1 outbreaks by developing an effective vaccine. It will also provide important data to guide policies on livestock vaccination, potentially reducing virus transmission. The project involves collaboration between the University of Guelph, the University of Toronto, the Canadian Food Inspection Agency, and the Ontario Ministry of Agriculture, Food and Rural Affairs.