Prevents the virus from attaching to epithelial cells by binding to the spike protein and promotes "immune exclusion," trapping pathogens in the mucus layer to prevent further spread
Elevated levels of SARS-CoV-2-specific sIgA in nasal secretions correlate with reduced viral load and decreased transmission risk.
- Brackett 2026: Early rise in nasal secretory IgA associated with shorter duration of SARS-CoV-2 virus shedding in an acute infection cohort
- Paul 2025: Mucosal immune responses to SARS-CoV-2 infection and COVID-19 vaccination
- Pisanic 2025: Early, robust mucosal secretory immunoglobulin A but not immunoglobulin G response to severe acute respiratory syndrome coronavirus 2 spike in oral fluid is associated with faster viral clearance and coronavirus disease 2019 symptom resolution
- Gagne 2024: Mucosal adenovirus vaccine boosting elicits IgA and durably prevents XBB.1.16 infection in nonhuman primates
- Liew 2023: SARS-CoV-2-specific nasal IgA wanes 9 months after hospitalisation with COVID-19 and is not induced by subsequent vaccination
- Mitsi 2023: Respiratory mucosal immune memory to SARS-CoV-2 after infection and vaccination