Highlights:
- Trajectory of long COVID in SARS-CoV-2 wild-type, Alpha, Delta, and Omicron
- Similar patterns of symptoms and severity of long COVID across all four variants
- No clinically significant decline in median severity up to 1.5 years after infection
- More than 50% of long COVID patients failed to improve using any outcome measure
- Patients infected with Omicron may experience severe non-improving long COVID
Abstract:
Objectives: Knowledge is limited on how changing SARS-CoV-2 variants may translate into different characteristics and affect prognosis of patients with long COVID, especially following Omicron variants. We compared long-term prognosis of patients in a Danish Post COVID Clinic infected with wild-type strain, Alpha, Delta, or Omicron variants as well as the pre-Omicron compared to the Omicron period.
Methods: At enrollment a Post COVID symptom Questionnaire (PCQ), and standard health scores, were registered, and repeated four times until 1.5 years after infection. PCQ was the primary outcome to assess severity of long COVID, and delta PCQ to assess failure to improve.
Results: A total of 806 patients were enrolled. Patients infected with Omicron and Delta variants presented with more severe long COVID (median PCQ 43 in Delta vs 38 in wild-type, P=0.003) and health scores (EQ5D-index was 0.70 in Omicron vs 0.76 in wild-type, P=0.009 and 0.78 pre-Omicron, P=0.006). At 1.5 year after infection patients had no clinically meaningful decline in severity of long COVID, and 57% (245/429) of patients failed to improve 1.5 years after infection, with no differences between variants.
Conclusions: More than half of patients referred to a Post COVID Clinic failed to improve in long COVID severity 1.5 years after infection regardless of variants of SARS-CoV-2.