Lower prevalence of post-Covid-19 Condition following Omicron SARS-CoV-2 infection

Objectives: Different SARS-CoV-2 variants can differentially affect the prevalence of Post Covid-19 Condition (PCC). This prospective study assesses prevalence and severity of symptoms three months after an Omicron infection, compared to Delta, test -negative and population controls. This study also assesses symptomology after reinfection and breakthrough infections. Methods: After a positive SARS-CoV-2 test, cases were classified as Omicron or Delta based on >= 85% surveillance prevalence. Three months after enrolment, participants indicated point prevalence for 41 symptoms and severity, using validated questionnaires for four symptoms. PCC prevalence was estimated as the difference in prevalence of at least one significantly elevated symptom, identified by permutation test, in cases compared to population controls. Results: At three months follow-up, five symptoms and severe dyspnea were significantly elevated in Omicron cases (n = 4138) compared to test -negative (n = 1672) and population controls (n = 2762). PCC prevalence was 10.4% for Omicron cases and 17.7% for Delta cases (n = 6855). In Omicron cases, severe fatigue and dyspnea were more prevalent in reinfected than primary infected, while severity of symptoms did not significantly differ between cases with a booster or primary vaccination course. Conclusions: Prevalence of PCC is 41% lower after Omicron than Delta at three months. Reinfection seems associated with more severe long-term symptoms compared to first infection.