Clinical Manifestations and Immunological Impacts in Co-Infections and Sequential Infections of SARS-CoV-2 and Arboviruses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and arboviruses represent major global public health threats, each with distinct epidemiological and pathogenic profiles that often overlap in endemic regions. Reports of co-infection and cross-reactivity between these viruses highlight the need for deeper understanding of their interactions. Co-infections pose diagnostic challenges due to overlapping clinical symptoms and immune modulation, which may exacerbate disease severity. Moreover, antibodies generated from prior virus infections may influence the outcome of subsequent infections through mechanisms such as cross-reactivity and antibody-dependent enhancement (ADE). This review summarises current knowledge on the clinical manifestations and immunological consequences of co- and subsequent infections involving SARS-CoV-2 and arboviruses. Emphasis is placed on underlying pathophysiological mechanisms, including cross-reactivity and ADE, that shape host immune responses. Understanding these interactions is essential for improving diagnostic accuracy and guiding public health strategies to mitigate the risks associated with co-infections and sequential viral infections.