Post-acute sequalae of COVID-19 three to twelve months after infection: Delta versus Omicron.

Abstract

Studies have shown temporal changes in Post-acute sequalae of COVID-19 (PASC) prevalence for early SARS-CoV-2 variants, though often lacking controls. This prospective study assesses the prevalence of symptoms in Delta and Omicron infected cases up to 12 months compared to population controls. Adult participants filled out three-monthly surveys (T0-T12) between July 2021 and August 2023. Cases were recruited with a positive SARS-CoV-2 test during Delta or Omicron domination. Population controls were randomly invited from the Dutch Personal Records Database. Participants indicated presence of 13 PASC-associated symptoms, and severity scores of fatigue, cognitive impairment, dyspnoea and pain. PASC prevalence was defined as the excess prevalence of having ≥ one PASC-associated symptom in cases compared to population controls. PASC prevalence was 34.3% at T3 and decreased to 21.7% at T12 for Delta and decreased from 18.7% at T3 to 16.7% at T12 for Omicron. At T12 the difference between Delta and Omicron was not significant. Delta cases generally had higher excess symptom scores for fatigue, dyspnoea and cognitive impairment than Omicron. In the first nine months after infection, PASC prevalence was higher for Delta than Omicron, but the difference reduced over time and approximated after twelve months.