Chikungunya resurgence highlights gaps in Aedes surveillance and control in South America

Over the past decade, chikungunya has re-emerged as a major public health concern in the Americas.1 In 2025 alone, more than 313,000 cases and 170 deaths were reported across 18 countries, according to the Pan American Health Organization (PAHO). Transmission continued to expand in 2026, particularly in Suriname, Bolivia, Brazil, and Argentina (Fig. 1). Although promising results have recently been obtained with chikungunya vaccines, several challenges still impede large-scale implementation, including the absence of WHO recommendations, safety concerns in certain populations, manufacturing and supply constraints, and limited data regarding efficacy, long-term protection, and optimal vaccination strategies for endemic areas and high-risk populations.