MedImmune, LLC, headquartered in Gaithersburg, Maryland, became a wholly owned subsidiary of AstraZeneca in 2007. Since being acquired, MedImmune has remained a Maryland-based biotechnology development enterprise. It produces Synagis, a drug for the prevention of respiratory infections in infants, which accounted for US$ 1.06 billion of its US$ 1.2 billion in revenue for 2005, and FluMist, a nasal spray influenza vaccine introduced in 2004.