Long COVID symptoms before and 3-35 months after SARS-CoV-2 infection in a Norwegian prospective cohort study, symptoms over the pandemic, and different virus variants.

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.