  The paper continues the study of the phenomenon of local immunodeficiency
(LI) in viral cross-immunoreactivity networks, with a focus on the roles and
interactions between altruistic and persistent viral variants. As always, only
the state of stable (i.e. observable) LI is analysed. First, we show that a
single altruistic viral variant has an upper limit for the number of persistent
viral variants that it can support. Our findings reveal that in viral
cross-immunoreactivity networks, altruistic viruses act essentially
autonomously from each other. Namely, connections between altruistic viruses do
not change neither their qualitative roles, nor the quantitative values of the
strengths of their connections in the CRNs. In other words, each altruistic
virus does exactly the same actions and with the same strengths with or without
presence of other altruistic viruses. However, having more altruistic viruses
allows to keep sizes of populations of persistent viruses at the higher levels.
Likewise, the strength of the immune response against any altruistic virus
remains at the same constant level regardless of how many persistent viruses
this altruistic virus supports, i.e. shields from the immune response of the
host's immune system. It is also shown that viruses strongly compete with each
other in order to become persistent in the state of stable LI. We also present
an example for a CRN with stable LI that only consists of persistent viral
variants.
