This market seeks to predict whether the H5N1 avian influenza virus will be officially declared a pandemic by the World Health Organization (WHO) by December 31st 2025.
For this question, the resolution will depend solely on an official WHO declaration of an H5N1 pandemic. Localized outbreaks, isolated cases, or regional epidemics will not qualify unless the WHO formally classifies the event as a pandemic.
The official website or public announcements of the WHO will serve as the primary source for determining the outcome of this market.
Not only is there currently no sign of a sustained human-to-human outbreak, but the WHO now has a category of "pandemic emergency", which is a higher standard than PHEIC. This new definition has only recently come into force, and I think that after all their communication challenges in 2020, WHO would be reluctant to call an outbreak a "pandemic" without declaring a "pandemic emergency".