The human immune repertoire retains the molecular memory of a very great diversity of target antigens (epitopes) and can recall this upon a second encounter with epitopes against which it has previously been primed. Although genetically diverse. proteins of coronaviruses exhibit sufficient conservation to lead to antigenic cross-reactions. In this review. https://www.bekindtopets.com/great-pick-Nobivac-Feline-1-HCPCh-special-find/