A NEW study has found that individuals who experience multiple COVID-19 infections are at greater risk of developing post-acute sequelae of COVID-19 (PASC), commonly known as long COVID.
Researchers analysed data from 2,511 frontline workers, primarily first responders, who had confirmed SARS-CoV-2 infections between March 2020–February 2024. Data were gathered from in-person questionnaires, surveys, medical records, and follow-up calls. Participants reporting persistent or new symptoms lasting at least 2 months beyond the acute phase of infection were classified as having PASC. Using a Poisson regression model, the study assessed the relationship between the risk of PASC and factors such as reinfection, disease severity, and vaccination status at the time of first infection.
The study identified 475 individuals with PASC, representing 18.9% of the cohort. The mean age of PASC patients was 54.8 years, comparable to those who did not develop the condition. Notably, 16.1% of participants had multiple COVID-19 infections. After adjusting for demographic and clinical factors, the researchers found that the risk of PASC was significantly higher among individuals with multiple infections (relative risk [RR]: 1.41). Severe COVID-19 was associated with an even greater risk (RR: 3.17), while those who were unvaccinated at first infection had the highest increased likelihood of developing PASC (RR: 3.29).
These findings highlight the long-term consequences of repeated COVID-19 infections and the protective effect of vaccination. While the precise mechanisms behind PASC remain unclear, clinicians should consider multiple infections and disease severity as key risk factors when managing patients with persistent symptoms.
Ada Enesco, EMJ
Reference
Babalola TK et al. SARS-COV-2 re-infection and incidence of post-acute sequelae of COVID-19 (PASC) among essential workers in New York: a retrospective cohort study. Lancet Reg Health Am. 2025;42:100984.
