Study shows measles wipes out 20 to 50% of antibodies against an array of viruses and bacteria, depleting a child’s previous immunity. Measles-ravaged immune system must ‘relearn’ how to protect the body against infections. Study details mechanism and scope of this measles-induced ‘immune amnesia.’ Findings underscore importance of measles vaccination, suggesting those infected with measles may benefit from booster shots of all previous childhood vaccines.