Tolerance is defined as an interaction in which viruses accumulate to some degree without causing significant loss of vigor or fitness to their hosts. Tolerance can be described as a stable equilibrium between the virus and its host. an interaction in which each partner not only accommodate trade-offs for survival but also receive some benefits (e. g. https://www.ealisboa.com/limited-value-AXYS-Valhalla-Pen-must-buy/