Merck and Themis, a company focused on vaccines and immune-modulation therapies for infectious diseases and cancer, have entered into a definitive agreement under which Merck, through a subsidiary, will acquire privately-held Themis.   Themis has a broad pipeline of vaccine candidates and immune-modulatory therapies developed using its innovative measles virus vector platform based on a vector originally developed by scientists at the Institut Pasteur, a European vaccine research institute, and ...