Langat Virus – A Hidden Player in the Tick-Borne Encephalitis Virus Family

Tick-borne flaviviruses pose a growing threat to global health, particularly in the context of climate-driven expansion of tick habitats. Among them, Tick-borne encephalitis virus (TBEV) is well known for causing severe neurological disease across Europe and Asia. In contrast, Langat virus (LGTV), a closely related member of the tick-borne encephalitis serocomplex, has remained largely in the shadows.

In her recent review, Prof. Klestova summarizes what we currently know about LGTV, from its natural tick vectors and rodent hosts to its ability to infect neurons and astrocytes. Although human infections are typically asymptomatic or mild, experimental studies show that LGTV can invade the central nervous system and induce neurological symptoms in animal models. Importantly, LGTV shares strong antigenic similarity with TBEV, leading to cross-reactive immune responses. These features have made LGTV an attractive model to study tick-borne flavivirus biology and even a potential backbone for live-attenuated TBEV vaccines. At the same time, rare cases of vaccine-associated neurological complications highlight the need for careful evaluation.

By identifying current knowledge gaps, including transmission routes, host range, and mechanisms of persistence, this review underscores why Langat virus deserves far greater scientific attention.

The review article was published in Reviews in Medical Virology and can be found here.

Image: Longhorned tick (Haemaphysalis longicornis), an experimental vector of Langat virus. Source: Wikimedia Commons; picture by James Gathany; public domain