Expanding: Emergent BioSolutions, a Maryland-based government contractor that helps maintain the U.S. stockpile of infectious disease vaccines, has agreed to pay $97.5 million to acquire the smallpox vaccine assets of pharmaceutical giant Sanofi. Acquisition: Red Hawk Fire & Security, a Florida-based fire and security services company, has bought Tele-Tector of Maryland, a 40-person Columbia firm founded in 1967 to provide similar services to health systems, corporations, government agencies and universities in the Washington and Baltimore area. Terms of the deal were not disclosed. New at the top: Delta Tucker Holdings named George Krivo chief executive of its McLean-based government contracting unit DynCorp International. Krivo, who previously served as chief operating officer, succeeds Lewis “Lou” Von Thaer, who took the CEO job at Battelle, a company that manages technology centers and national laboratories.