"pandemic" means the WHO recognizes the spread of the pathogen as a pandemic.

"engineered" means that the pathogen was altered/created by humans. This includes wild diseases that were modified (e.g. gain-of-function research).

the "pathogen" must be novel. For example, if COVID-19 were shown to have been engineered, this news would not affect this question.

The humans responsible for the pathogen can be any group; e.g. that includes leaks from labs, as well as the release of an engineered pathogen by a non-lab actor (e.g. terrorists, amateur geneticists).

The anthropogenic origins of the pathogen must be relatively certain; e.g. clear majority of mainstream press outlets, governments, and/or scientists agree the pandemic was engineered.