Turning the tables on ticks: How scientists are unlocking immune responses to prevent Lyme disease

When a blacklegged tick (Ixodes scapularis) bites into human skin, it does more than simply take a blood meal. Through its saliva, the tick injects a complex cocktail of proteins designed to suppress the host’s immune response and secure its position for an extended feast. Among these are immunosuppressive proteins that help the tick go unnoticed, and cement-like substances that anchor its mouthparts to the skin. This insidious process is not just about feeding. It’s also a biological backdoor for dangerous pathogens such as Borrelia burgdorferi, the bacteria responsible for Lyme disease. In most cases, these proteins allow the tick to stay attached for several days, a window of time during which transmission of disease becomes increasingly likely. But the human immune system can learn. For some individuals, repeated tick bites provoke an adaptive immune response that transforms the experience. “Tick bites kind of hurt or itch” in people who’ve developed this...