Natural viruses are quite like computer viruses.
Your body can get out of sync with natural virus populations.
A good example is the flu and flu shots, which attempt to resync your body to the flu virus population.
Out of sync? What does that even mean?
What are the structural, functional, or biochemical changes that take place within macrophages, neutrophils, dendritic cells, T-cells, or B-cells that act as a mechanism for the immune system becoming any less effective when exposed to fewer microbes?