Ex Virus toughens up cells, works through the brain

“The ex-virus toughens up cells, makes them hardier. So while the person dies, their individual cells don’t break down as fast, and the dead body continues on as a gigantic aggregate of living cells joined by the virus.”
“But how?”
“Still working on that one. There’s a good chance we’ll never know for sure. The ex-virus doesn’t behave like anything else on record and we don’t have the resources to study it more in depth than we are. It seems to involve the central nervous system as people have suspected from the start. That’s why destroying the brain is the only thing that stops them—the virus is all through the body, but it primarily resides in the brain and sends impulses along the nerves. You’ll still have the enhanced cells, but nothing stimulating them into action.”

Excerpt From Ex-Heroes, pg 188-189
Peter Clines
https://books.apple.com/us/book/ex-heroes/id585738407