Effect of SARS-CoV-2 vaccination on symptoms from post-acute COVID syndrome: results from the national VAXILONG survey

Introduction: Few data are available concerning the effect of SARS-CoV-2 vaccination on the persistent symptoms associated with COVID-19, also called long-COVID or post-acute COVID-19 syndrome (PACS). Patients and methods: We conducted a nationwide online survey among adult patients with PACS as defined by symptoms persisting over 4 weeks following a confirmed or probable COVID-19, without any identified alternative diagnosis. Information concerning PACS symptoms, vaccine type and scheme and its effect on PACS symptoms were studied. Results: Six hundred and twenty surveys were completed and 567 satisfied the inclusion criteria and were analyzed. Respondents were 83.4% of women of median age 44 (IQR 25-75: 37-50). Initial infection was proven in 365 patients (64%) and 5.1% had been hospitalized to receive oxygen. 396 patients had received at least one injection of SARS-CoV-2 vaccine at the time of the survey, after a median of 357 [198-431] days following the initially-reported SARS-CoV-2 infection. Among the 380 patients who reported persistent symptoms at the time of SARS-CoV-2 vaccination, 201 (52.8%) reported variation of symptoms following the injection, without difference based on the type of vaccine used. After a complete vaccination scheme, 93.3% (28/30) of initially seronegative patients reported a positive anti-SARS-CoV-2 IgG. 170 PACS patients had not been vaccinated. The most common reasons for postponing SARS-CoV-2 vaccine were a fear of worsening PACS symptoms (55.9%) and the idea that vaccination was contraindicated because of PACS (15.6%). Conclusion: Our study suggests that SARS-CoV-2 vaccination is well tolerated in the majority of PACS patients and has good immunogenicity. Disseminating these reassuring data might prove crucial to increase vaccine coverage in patients with PACS.