Measles Virus Infection: Mechanisms of Immune Suppression

Measles virus (MV) is a highly contagious respiratory pathogen that causes systemic disease; most individuals recover with lifelong immunity to MV. Enormous progress toward measles elimination has been made worldwide, in large part due to the availability of a safe and effective vaccine (CDC, 2000; WHO, 2005; 2009; 2010). However, measles infections still cause 500,000 deaths annually, mostly due to subsequent opportunistic infections associated with MV induced immune-suppression (Wild, 1999). Prior to the introduction of vaccines and a global eradication programme coordinated by the World Health Organisation (WHO) (Wild, 1999), global death rates were as high as 7–8 million children annually. The introduction of a live measles vaccine has significantly reduced the incidence of acute measles in industrialized countries. In developing countries however, measles is still an important health problem and the major viral killer of children.