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Characterization of post-COVID syndrome by self-perceived symptom severity stratified by infection wave: beyond

Alexander Mertens¹, Judith Smith², Ingmar Bergs²

¹Department of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty of Heinrich Heine, University Hospital Düsseldorf, University Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.

|May 18, 2026

Abstract

Background:

Post-COVID syndrome (PCS) refers to persistent or new-onset symptoms 3 months after SARS-CoV-2 infection lasting for at least 2 months. The characterization of PCS varies across studies, with a substantial heterogeneity regarding different study samples, survey instruments, and follow-up periods. This is particularly the case in hospitalized patients vs. outpatients, as well as regarding different variants of concern (VOCs) and their impact on the frequency and severity of specific symptoms.

Methods:

The study population of Beyond COVID was recruited in six German cities by inviting (1) individuals registered as SARS-CoV-2 PCR positive at the local Public Health Authorities and (2) previously hospitalized patients with infection date after 1st March 2021. Participants were allocated to the predominant VOC of their first infection. Questionnaires to assess pre-existing conditions, symptoms during infection, and persisting symptomswere performed. Follow-up at sixth-month intervals is planned for 3 years. The study is ongoing. This publication describes the parameters at the baseline visit (BV).

Results:

We included 1257 participants (13% hospitalized-based; 87% population-based). Most participants had BA.2 (n = 436; 35%), followed by Delta (n = 336; 27%), BA.1 (n = 238; 19%), and Alpha (n = 218; 17%). The mean age was 47.1 years, and 59% of the participants were female. 72% reported at least one persisting symptom. Fatigue was the most frequent ongoing symptom (33%), followed by concentration disorders (25%) and dyspnoea (22%). Female sex, lower education, and a shorter period between infection and BV were associated with higher rates of persisting symptoms and symptom severity. Among all VOCs, participants with BA.1 and BA.2 had the lowest rates of persisting symptoms and symptom severity.

Conclusion:

Analysis of baseline data from the Beyond-COVID cohort confirms a high percentage of persistent symptoms. Omicron variants had lower rates of persistent symptoms and symptom severity. We are confident, that long-term follow-up and the additional results from our clinical examinations, blood samples, sociodemographic and psychosocial data will further contribute to the characterization of PCS.

Keywords:

Alpha COVID-19 COVID-long-term COVID-waves Delta Follow-up after COVID-19 Gender association in post-COVID-19 Long COVID Long COVID-19 Omicron PCC PCS Persistence of COVID-19 symptoms Post COVID Post COVID Condition Post acute sequelae of SARS CoV-2 infection SARS-CoV-2 VOC VOCs Variant of Concern Wave-association

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