One Health and the potential of H5N1 jumping from Birds to Humans
Daniel Perez, PhD discusses avian influenza viruses. Some, such as the H5N1 are highly pathogenic and have low infectivity in humans while others have low pathogenicity such as the H9N2 virus but are highly infectious in humans. Even though the H5N1 has caused a massive avian pandemic, there are relatively few cases in humans in the past 6 years compared to 2015 and before. Thus, the risks to humans are low, but there is significant concern regarding risks to our food supply. Whole inactivated virus adjuvanted vaccines gave a stronger immunological response than modified attenuated viral vaccines. However, immunomodulators can increase the response to attenuated viral vaccines. Vaccination of poultry is labor intensive. The use of attenuated live viral vaccines has distinct advantages in agriculture. In addition, some countries will not import vaccinated poultry.

Several lessons can be learned regarding our current pandemic.
1. The geographic breadth and size of the current N5H1 pandemic is of significant concern regarding possible emergence of new variants which have increased adaption for infection of humans and mammals.
2. Viral mutations and new clades do not necessarily mean lower pathogenicity.
3. Animal reservoirs can cause the recurrence of a viral strain which became extinct in humans. This happened with the H1N1 influenza virus.

Health Watch USA(sm) meeting March 15, 2023.