The Effect of SARS-CoV-2 Vaccination on Post-Acute COVID-19 Syndrome (PACS): A Prospective Cohort Study

Background: Symptoms of post-acute COVID-19 syndrome (PACS) may improve following SARS-CoV-2 vaccination, however few data that also explore the underlying biological mechanism exist. We assessed the effect of vaccination on symptomatology of participants with PACS, and compared antibody dynamics between those with and without PACS.Methods: RECoVERED is a prospective cohort study of adult patients with mild to critical COVID-19. Among participants with PACS, vaccinated participants were exact-matched 1:1 on age, sex, obesity status and time since illness onset, to unvaccinated participants. Between matched pairs, we compared mean numbers of symptoms over time, and, using exact logistic regression, proportion fully recovered by 3 months. We assessed the association between PACS status and rate of decay of spike- and RBD-binding IgG titers up to 9 months after illness onset.Findings: Of 349 participants enrolled, 316 (90·5%) had ≥3 months of follow-up, of whom 186 (58·9%) developed PACS. Among 36 matched pairs with PACS, the mean number of reported symptoms during 3 months of follow-up were comparable between vaccinated and unvaccinated groups. Odds of full recovery from PACS also did not differ between matched pairs (OR 1·57 [95%CI 0·46-5·84]). The median half-life of spike- and RBD-binding IgG levels were, in days (95%CrI), 233 (183-324) and 181 (147-230) among participants with PACS, and 170 (125-252) and 144 (113-196) among those without PACS.Interpretation: Our study found no strong evidence to suggest vaccination improves symptoms of PACS. This was supported by comparable spike- and RBD-binding IgG waning trajectories between those with and without PACS.Funding Information: This work was supported by the Netherlands Organization for Health Research and Development (ZonMw) (RECoVERED, grant agreement numbers 10150062010002 to M.D.d.J. and 10430072110003 to G.J. de Bree) and the Public Health Service of Amsterdam (Research & Development grant number 21-14 to M. Prins). Declaration of Interests: All authors declare no competing interests.Ethics Approval Statement: Written informed consent was obtained from each study participant. The study design was approved by the local ethics committee of the Amsterdam UMC (Medisch Ethische Toetsingscommissie [METC]; NL73759.018.20).