<p>Parasitological methods.</p>

Study procedures included diagnostics for loiasis and immunological assays. Microfilaremia was confirmed by stained blood smear microscopy, and occult disease was identified using the Rapid Assessment Procedure for Loiasis. SARS-CoV-2-specific IgG responses to spike and nucleocapsid proteins were measured by ELISA, and IFN-γ responses to spike antigen were assessed using an interferon-gamma release assay.</p> <p>Results</p><p>Overall, 192 participants were categorized as microfilaremic (n = 43), occult loiasis (n = 59), or without evidence of active loiasis (n = 90).

IFN-γ responses were reduced in microfilaremic individuals compared with other participants (<i>p</i> = 0.031), whereas IgG responses did not differ. Subsequent analysis across the three groups confirmed that IFN-γ responses were lower in microfilaremic compared with occult participants (<i>p</i> = 0.012).</p> <p>Conclusion</p><p>These findings suggest that microfilaremic loiasis may impair proinflammatory T cell responses to viral antigens, highlighting the need for further research into the broader immunological effects of <i>Loa loa</i> infection in endemic populations.</p></div>