Chikungunya Virus in 2025: Epidemiology, Immunopathogenesis, and Vaccine Development — A Narrative Review

Chenxi Zhao,* Ziruo Ge,* Tingyu Zhang, Zhouling Jiang, Di Tian, Zhihai Chen National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhihai Chen, National Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China, Email chenzhihai0001@126.com Di Tian, National Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China, Email tiandi412@hotmail.comAbstract: Chikungunya is an arboviral disease caused by infection with chikungunya virus (CHIKV), an alphavirus transmitted primarily by Aedes aegypti and Aedes albopictus. Over the past two decades, chikungunya has re-emerged across Africa, Asia, the Indian Ocean, Europe, and the Americas, with 119 countries and territories reporting local transmission up to 2024. This expansion reflects a widening geographic range with greater risk of introduction and spreads through mosquito vectors, leaving larger populations susceptible to infection. Following inoculation by an infected mosquito, viral replication leads to viremia and the abrupt onset of fever, severe joint pain with swelling, myalgia, and rash. These clinical manifestations are driven by the host immune response to infection, which also influence disease severity and clinical outcomes. Although most patients recover within weeks, a proportion develop persistent arthralgia or chronic arthritis lasting months to years, contributing to the overall disease burden. Although both the live-attenuated vaccine IXCHIQ and the virus-like particle vaccine VIMKUNYA have been approved, the license for IXCHIQ was recently suspended due to safety concerns. Recent outbreaks of chikungunya fever have driven sustained research, leading to deeper insights into disease pathogenesis, host immune responses and chronic inflammation. In this narrative review, we summarize recent advances up to 2025 in the epidemiology, host receptors, pathogenesis, clinical manifestations, immune responses, mother-to-child transmission, and vaccines development of CHIKV. Keywords: chikungunya, arthritis, cytokine, mother-to-child transmission, vaccine