claim: coronavirus hemagglutinin-esterase and spike proteins coevolve for functional balance and blocking virion avidity
evidence_1: structure, function and evolution of the hemagglutinin-esterase proteins of corona- and toroviruses.", "human coronavirus hku1 spike protein uses o-acetylated sialic acid as an attachment receptor determinant and employs hemagglutinin-esterase protein as a receptor-destroying enzyme.")