Efficacy of COVID-19 Vaccination on the Symptoms of Patients With Long COVID: A Target Trial Emulation Using Data From the ComPaRe e-Cohort in France

Background: Long COVID is a complex multiorgan disorder that can affect patients’ lives severely. Recent reports suggest symptoms improve after COVID-19 vaccination.  Methods: We used data from the ComPaRe long cohort to emulate target trial evaluating effect of vaccination among patients with who still had persistent at baseline. Vaccinated were matched unvaccinated controls in 1:1 ratio by their propensity scores. Outcomes, all measured 120 days baseline, include disease severity (long ST, range 0-53), rate complete remission (ie, disappearance symptoms), impact on covid IT, 0-60), and proportion reporting an unacceptable symptom state. reported adverse events occurring free text.  Findings: In total, 455 allocated group control group; 545 (60·1%) confirmed infections, 81 (8·9%) been hospitalized during acute COVID-19. By days, reduced (mean (SD) ST score 13·0 (9·4) vs. 14·8 (9·8) mean difference: -1·8, 95% CI -2·5 -1·0) doubled (remission 16·6% vs 7·5%, HR: 1·97, 1·23 3·15). Furthermore, both IT 24.3 (16·7) 27·6 (16·7); -3·3, -6·2 -0·5) state (38.9% 46.4%, risk difference -7·5%, -14·4 -0·5). group, two (0·4%) serious leading hospitalisation.  Interpretation: lowers life symptoms. Funding Information: The authors received no specific funding for this work. Declaration Interests: declare competing interests financial associations may be relevant or seen as submitted manuscript. have association commercial entities could viewed having interest general area manuscript. Ethics Approval Statement: All provided online consent before participating cohort. Institutional Review Board Hotel-Dieu Hospital, Paris, approved study (IRB: 0008367).