Chikungunya Virus: Priority Pathogen or Passing Trend?

Abstract

Chikungunya virus (CHIKV) is considered a priority pathogen and a major threat to global health. While CHIKV infections may be asymptomatic, symptomatic patients can develop chikungunya fever (CHIKF) characterized by severe arthralgia which often transitions into incapacitating arthritis that could last for years and lead to significant loss in health-related quality of life. Yet, Chikungunya fever (CHIKF) remains a neglected tropical disease due to its complex epidemiology and the misrepresentation of its incidence and disease burden worldwide. Transmitted to humans by infected Aedes mosquitoes, CHIKV has dramatically expanded its geographic distribution to over 100 countries, causing large-scale outbreaks around the world and putting more than half of the population of the world at risk of infection. More than 50 years have passed since the first CHIKV vaccine was reported to be in development. Despite this, there is no licensed vaccine or antiviral treatments against CHIKV to date. In this review, we highlight the clinical relevance of developing chikungunya vaccines by discussing the poor understanding of long-term disease burden in CHIKV endemic countries, the complexity of CHIKV epidemiological surveillance, and emphasising the impact of the global emergence of CHIKV infections. Additionally, our review focuses on the recent progress of chikungunya vaccines in development, providing insight into the most advanced vaccine candidates in the pipeline and the potential implications of their roll-out.

Keywords: Alphavirus; Chikungunya virus (CHIKV); chikungunya vaccine; clinical trial; epidemiology; mosquitoes.

Figure 1

Overlapping distribution of the Chikungunya virus and the probability of occurrence of Aedes mosquitos (A. aegypti and A. albopictus). Originally identified in Tanzania in 1952 (red), CHIKV has been reported in over 100 countries in Africa, Asia, the Pacific, Oceania, the Americas, and the Caribbean (light green). The expansion of CHIKV’s geographical distribution across the globe has been perpetuated by the presence of Aedes mosquitos in non-endemic regions. The widespread distribution of CHIKV’s most common vectors (A. aegypti and A. albopictus) puts half of the world’s population at risk of infection (dark green).