Abstract
COVID-19 pandemic continues to challenge the world with a major public health problem, long COVID (LC), which is estimated to affect over 400 million people worldwide. Many unknowns remain regarding the mechanisms involved in LC. We investigated the impact of anti-SARS-CoV-2 antibody and IFN-γ responses on the development of LC and its various phenotypes. We studied a cohort of 137 convalescents following predominantly mild COVID-19 during the first pandemic wave (2020) and up to one-year post-infection. We found 45% of LC cases that were associated with a greater number and duration of acute-phase symptoms. Cardiovascular and/or gastrointestinal symptoms in the acute phase were associated to protection against LC development, while pulmonary, otorhinolaryngological, musculoskeletal and other symptoms were associated with increased risk of LC development. Regarding LC phenotypes, we observed risk associations and potentially deleterious effects of anti-SARS-CoV-2 antibodies for LC symptoms classified as general or other. In contrast, for vital organ-related LC symptoms, we found only protective associations, particularly for cardiovascular symptoms, which indeed had a low prevalence in LC (16%). Collectively, our data suggest that anti-SARS-CoV-2 antibodies play a protective role against vital organ-related LC symptoms, especially cardiovascular symptoms, but are insufficient in preventing or limiting other highly prevalent LC symptoms, such as neurological, psychiatric and pulmonary.