The metaphor of a simmering / boiling-over is used to characterise (explain) the emergence of COVID-19 virus as a sociological/political (and not biological) phenomenon. In doing so, the virus' emergence is blamed on actors antagonistic to social conservatives e.g. (radical)
#CauseFeminism,
#PoliticallyCorrectPC, CancelCulture and the
#MetaphorWarfareSocialJusticeWarriorSJW.