ObjectiveVaccination decreases the risk of severe COVID-19 but its impact on postacute sequelae of COVID-19 (PASC) is unclear among patients with systemic autoimmune rheumatic diseases (SARDs) who may have blunted vaccine immunogenicity and be vulnerable to PASC.MethodsWe prospectively enrolled patients with SARD from a large healthcare system who survived acute infection to complete surveys. The symptom-free duration and the odds of PASC (any symptom lasting ≥28 or 90 days) were evaluated using restricted mean survival time and multivariable logistic regression, respectively, among those with and without breakthrough infection (≥14 days after initial vaccine series).ResultsAmong 280 patients (11% unvaccinated; 48% partially vaccinated; 41% fully vaccinated), the mean age was 53 years, 80% were female and 82% were white. The most common SARDs were inflammatory arthritis (59%) and connective tissue disease (24%). Those with breakthrough infection had more upper respiratory symptoms, and those with non-breakthrough infection had more anosmia, dysgeusia and joint pain. Compared with those with non-breakthrough COVID-19 infection (n=164), those with breakthrough infection (n=116) had significantly more symptom-free days over the follow-up period (+21.4 days, 95% CI 0.95 to 41.91; p=0.04) and lower odds of PASC at 28 and 90 days (adjusted OR, aOR 0.49, 95% CI 0.29 to 0.83 and aOR 0.10, 95% CI 0.04 to 0.22, respectively).ConclusionVaccinated patients with SARDs were less likely to experience PASC compared with those not fully vaccinated. While we cannot rule out the possibility that findings may be due to intrinsic differences in PASC risk from different SARS-CoV-2 variants, these findings support the benefits of vaccination for patients with SARDs and suggest that the immune response to acute infection is important in the pathogenesis of PASC in patients with SARDs.