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.