Laura Garcia, Victor Yman, Marie-Fabrice Gasasira, Françoise Donnadieu, Jason Rosado, Lucie Cappuccio, Damien Hoinard, Philippe Desprès, Stéphane Petres, Jean-Claude Manuguerra, In-Kyu Yoon, Taweewan Hunsawong, Maria Theresa P Alera, Emily S Gurley, Nikos Vasilakis, Scott C Weaver, Ziaur Rahman, Ilaria Dorigatti, Chris Drakeley, Inès Vigan-Womas, Makhtar Niang, Henrik Salje, Jessica Vanhomwegen, Michael White
Arboviruses such as dengue virus (DENV) and chikungunya virus (CHIKV) pose major global health threats. To support serological surveillance and study cross-reactivity, an in-house multiplex bead-based immunoassay was developed to measure IgG responses against a wide panel of orthoflavivirus and alphavirus antigens. Samples from Senegal, France, the Philippines, and Bangladesh enabled analyses to be carried out in endemic and non-endemic regions. IgG kinetics following DENV1 and CHIKV infections revealed virus-specific temporal profiles and identified antigens, such as CHIKV E2 and VLP, as well as DENV1 EDIII and SNAP-tagged EDIII, as promising markers for serosurveillance. A two-step Random Forest model was used to classify PRNT-positive samples and predict PRNT titers. CHIKV showed a strong correlation between IgG and PRNT titers (R² = 0.71), while DENV1 showed weaker performance (R² = 0.42). These results support the use of multiplex serology for arbovirus surveillance and highlight the limitations of using binding antibodies to predict neutralisation, particularly for orthoflaviviruses.