Robert Ludlum's The Hades Factor: A Covert-One Novel (2006)

While the writing and the unrolling of the plot is a bit too flowery, the main theme would still be an interest (in particular for conspiracy theorists). Could it be possible for some (private in this case) organization to unleash a virus on the world's population for which they only have the serum to heal, and make an enormous profit as governments buy them out. With the advances in biotechnology, this might be becoming a closer possibility ...