A process in which a symbiont interferes with, inhibits or disrupt a JAK-STAT signal cascade in the host organism by reducing the activity of host TYK2 (tyrosine kinase 2). TYK2 is an intracellular signal-transducing tyrosine kinase involved in numerous cytokines and interferons signaling pathways and transmits the cytokine signal by phosphorylating receptor subunits.
suppression by virus of host JAK-STAT cascade via inhibition of host TYK2 activity