Measles is one of the most contagious and devastating viral diseases. However, highly effective live vaccines have been successfully used for more than five decades. Recent structural studies of measles virus hemagglutinin and its complexes with receptors (the signaling lymphocyte activation molecule (SLAM, CD150) and CD46) have provided many insights into measles virus entry mechanism. Furthermore, the sugar shields that cover the large surface areas of the hemagglutinin have implications for effective measles virus vaccination. These studies should help strengthen current global efforts to control and eliminate measles worldwide.