 In sum, the ecological view has led to the view that boundaries between parasitism, commensalism and mutualism are changeable and fluid, dependent on host factors, the full microbiota, and the broader environmental context (temperature, nutrients, etc.) (Méthot and Alizon 2014). Current views of plasticity, pathogenicity, and virulence revitalizes the nineteenth-century concept of microbial-host equilibrium (Méthot 2012). In the context of disease ecology, long-lasting associations between hosts and parasites leads to a climax state in which the respective populations remain stable (Burnet and White 1972; Anderson 2004). The immune equilibrium model then depicts persistent viral colonization as a product of a “dynamic but metastable equilibrium between the virome and the host” (Virgin, Wherry, and Ahmed 2009; Eberl 2010). Thus, the modern idea of balance highlights a stable state in which offensive and defensive forces neutralize one another to form stable associations between parasites and the host with little damage to either partner (Swiatczak 2014).