Well, there are two more things to consider. One is Interferon. Infection
of a host by a virus will cause the release of Interferon(s) which will, in
theory, reduce (interfere with and hence the name) the infectivity of a
secondary viral infection. Second, the host should be able to handle any
number of immune perturbations at the same time. Thank goodness for that or
we would have a harder time surviving in the environment loaded with all the
infectious microbiological agents we have.
