Pathogenesis of influenza and SARS-CoV-2 co-infection at the extremes of age: decipher the ominous tales of immune vulnerability

Abstract

The co-circulation of influenza and SARS-CoV-2 has led to co-infection events, primarily affecting children and older adults, who are at higher risk for severe disease. Although co-infection prevalence is relatively low, it is associated with worse outcomes compared to mono-infections. Previous studies have shown that the outcomes of co-infection depend on multiple factors, including viral interference, virus-host interaction and host response. Children and the elderly exhibit distinct patterns of antiviral response, which involve airway epithelium, mucociliary clearance, innate and adaptive immune cells, and inflammatory mediators. This review explores the pathogeneses of SARS-CoV-2 and influenza co-infection, focusing on the antiviral responses in children and the elderly. By comparing immature immunity in children and immune senescence in older adults, we aim to provide insights for the clinical management of severe co-infection cases.

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Funding

National Natural Science Foundation of China(82361168672)

National Natural Science Foundation of China(82174053)

National Natural Science Foundation of China(82341099)

Science and Technology Development Fund of Macau SAR, China(FDCT0111/2023/AFJ)

Science and Technology Development Fund of Macau SAR, China(005/2022/ALC)

Science and Technology Development Fund of Macau SAR, China(0045/2021/A)

Open Project of State Key Laboratory of Respiratory Disease(SKLRD-OP-202209)

Self-supporting Program of Guangzhou Laboratory(SRPG22-007)

RIGHTS & PERMISSIONS

The Author(s)