The Jason Strain(2006)
(The fourth book in the Friday the 13th (Black Flame) series)
A novel by Christa Faust
A controversial new reality TV show pits convicts against each other in a fight to the death, and Jason has been lured as the show's star attraction. However, an eccentric millionaire wants to get a sample of Jason's DNA to find the secret of his immortality, but it all goes horribly wrong. The "Jason Strain", a highly contagious virus that makes its victims invulnerable and immortal, but also fills them with Jason's rage and desire to kill, is unleashed upon the unsuspecting contestants!
Used availability for Christa Faust's The Jason Strain
January 2006 : UK Mass Market Paperback