Most individuals with long COVID continued to experience symptoms more than two years after initial infection, according to findings from a study.
Researchers found that only 1.8% of patients with long COVID reported resolution of symptoms, while the majority continued to have worse physical and mental health outcomes compared with those who never developed long COVID.
Using participants from the Innovative Support for Patients with SARS-CoV-2 Infections Registry (INSPIRE) cohort, investigators followed 3,663 adults who tested positive for SARS–CoV-2 between December 2020 and August 2022. As of April 2024, 27.1% of participants reported ongoing long COVID, 1.8% reported resolved long COVID, and 71.1% reported no history of long COVID symptoms.
Participants with current long COVID demonstrated significantly worse health status. Compared with those without long COVID, they had lower PROMIS-29 physical health scores by 7.8 points and lower mental health scores by 9.4 points. They also had higher odds of moderate-to-high stress, moderate-to-high loneliness, moderate-to-severe fatigue, and dyspnea.
Among patients reporting ongoing long COVID, symptom trajectories varied: 47% reported waxing and waning symptoms, 26% reported improvement, 19% reported no change, and 8% reported worsening symptoms.
Researchers also examined the impact of COVID-19 vaccination on health outcomes. Patients vaccinated prior to the development of long COVID had significantly better physical and mental health scores. Greater numbers of vaccine doses (0, 1–2, 3–5, 6 or higher) were associated with progressively better health outcomes across all measures.
"The majority of people with long COVID may not experience complete resolution," wrote first study author Michael Gottlieb, MD, of Rush University Medical Center, and colleagues. Among participants with ongoing illness, the mean duration of long COVID symptoms exceeded two years.
Participants who reported resolved long COVID showed partial recovery but continued to experience moderately worse health compared with those who never had long COVID; their physical health scores were 2.0 points lower and mental health scores were 2.3 points lower.
Health status and outcomes were evaluated using validated instruments, including PROMIS-29, the Fatigue Severity Scale, the Perceived Stress Scale, and the UCLA Loneliness Scale. Participants were recruited from diverse U.S. healthcare settings and completed quarterly surveys throughout the study period.
The authors noted several limitations, including reliance on self-reported long COVID status, potential recall bias, and limited adjustment for comorbidities beyond age and sex.
The research was funded by the Centers for Disease Control and Prevention. Full disclosures are available in the original study.