Thank you for your response. Actually, evolution has evolved a separate immune system for the brain, composed mainly of tissue-resident macrophages, that handle the lion's share of anti-infective strategies. This is distinct from the blood-borne immune system. While the blood-borne immune system's main tactic against viruses is to either apoptose or ingest the infected cell, the brain's immune system takes a radically different approach.
The brain's immune system focuses on containing the spread of the infection and triggering intracellular processes in the infected neurons that would