Measles Immune Suppression: Functional Impairment or Numbers Game?

Measles remains a significant cause of childhood morbidity and mortality. Hallmark of the disease is a generalized immune suppression that can last for several weeks to months after resolution of measles virus (MV) infection [1–3], resulting in increased susceptibility to opportunistic infections [4–7]. At the same time, measles is associated with immune activation and induces strong MV-specific immune responses that confer lifelong immunity [8]. This contradiction is known as the ‘‘measles paradox’. Although measles-associated immune suppression has been a subject of study since the beginning of the 20th century [9], the importance of possible underlying mechanisms remains disputed.