Objectives: Examine long COVID symptoms and prevalence of symptoms over the pandemic and compare symptoms due to the Omicron variants with symptoms due to earlier variants of the SARS-CoV-2 virus.
Methods: In the present Norwegian prospective cohort study, 11,5737 persons, aged 18-96 years, completed 1-6 questionnaires 3-35 months after a positive and/or negative SARS-CoV-2 test between 2020 and 2023.
Results: The following symptoms were reported more frequently 3-35 months after than before a positive SARS-CoV-2 test (n = 37,400): worsening of health, (odds ratio [OR] 1.79 [confidence interval (CI) 1.71-1.86]), memory problems (2.21 [2.06-2.37]), concentration problems (1.98 [1.87-2.09]), dyspnea (1.95 [1.84-2.07]), fatigue (1.46 [1.41-1.52]), and smell/taste changes (3.12 [2.84-3.42]). The prevalence of symptoms was lower at the end of 2022 than in 2020. A positive SARS-CoV-2 test during the Omicron-dominated period was associated with lower prevalence of symptoms than a positive test during the period dominated by earlier variants.
Conclusions: Several symptoms lingered up to 35 months after SARS-CoV-2 infection. The prevalence of symptoms decreased over the course of the pandemic and were reported less often in those infected with later SARS-CoV-2 variants than earlier variants. The indications of long-term persisting symptoms after COVID-19 and the consequences of new variants should be further monitored.
Keywords: Delta; Long COVID; Omicron; SARS-CoV-2; Symptoms.
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