BackgroundDespite the overall safety and efficacy of COVID‐19 vaccinations, rare cases of systemic autoimmune diseases (SAIDs) have been reported post‐vaccination. This study used a global survey to analyze SAIDs in susceptible individuals' post‐vaccination.MethodsA cross‐sectional study was conducted among participants with self‐reported new‐onset SAIDs using the COVID‐19 Vaccination in Autoimmune Diseases (COVAD) 2 study dataset—a validated, patient‐reported e‐survey—to analyze the long‐term safety of COVID‐19 vaccines. Baseline characteristics of patients with new‐onset SAIDs and vaccinated healthy controls (HCs) were compared after propensity score matching based on age and sex in a 1:4 ratio.ResultsOf 16 750 individuals, 74 (median age 52 years, 79.9% females, and 76.7% Caucasians) had new‐onset SAID post‐vaccination, mainly idiopathic inflammatory myopathies (IIMs) (n = 23, 31.51%), arthritis (n = 15; 20.53%), and polymyalgia rheumatica (PMR) (n = 12, 16.40%). Higher odds of new‐onset SAIDs were noted among Caucasians (OR = 5.3; 95% CI = 2.9–9.7; p < .001) and Moderna vaccine recipients (OR = 2.7; 95% CI = 1.3–5.3; p = .004). New‐onset SAIDs were associated with AID multimorbidity (OR = 1.4; 95% CI = 1.1–1.7; p < .001), mental health disorders (OR = 1.6; 95% CI = 1.3–1.9; p < .001), and mixed race (OR = 2.2; 95% CI = 1.2–4.2; p = .010), where those aged >60 years (OR = 0.6; 95% CI = 0.4–0.8; p = .007) and from high/medium human development index (HDI) countries (compared to very high HDI) reported fewer events than HCs.ConclusionThis study reports a low occurrence of new‐onset SAIDs following COVID‐19 vaccination, primarily IIMs, PMR, and inflammatory arthritis. Identified risk factors included pre‐existing AID multimorbidity, mental health diseases, and mixed race. Revaccination was well tolerated by most patients; therefore, we recommend continuing COVID‐19 vaccination in the general population. However, long‐term studies are needed to understand the autoimmune phenomena arising post‐vaccination.