Vaccine-Associated Anterior Uveitis

Vaccine-associated anterior uveitis (VAAU) is an uncommon ocular inflammatory phenotype reported after several vaccine platforms. It describes anterior segment inflammation occurring after vaccination when infectious, autoimmune, idiopathic, medication-related, and other possible causes have been reasonably excluded. The current literature indicates that post-vaccination uveitis is rare relative to the scale of immunization, although anterior uveitis is frequently reported among post-vaccination ocular inflammatory events. Evidence remains limited by reliance on case reports, case series, retrospective cohorts, and passive surveillance data, which restricts precise incidence estimation and causal interpretation. Accordingly, the available evidence primarily supports a temporal association rather than a confirmed causal relationship. Proposed mechanisms include innate immune activation, molecular mimicry, adjuvant- or formulation-related immune stimulation, bystander activation, delayed-type hypersensitivity, and host susceptibility related to prior uveitis, autoimmune disease, immune dysregulation, or genetic predisposition. Clinically, VAAU may present with redness, pain, photophobia, blurred vision, anterior chamber cells and flare, keratic precipitates, posterior synechiae, elevated intraocular pressure, vitritis, or cystoid macular edema. Most cases described in the literature are mild to moderate and improve with topical corticosteroids and cycloplegic therapy, whereas recurrent, severe, or treatment-intensive courses have been reported mainly in predisposed individuals. Future work should emphasize active surveillance, standardized phenotype-specific reporting, harmonized case definitions, and mechanistic studies to better define risk, recurrence patterns, and causality. Careful interpretation of suspected cases can support accurate diagnosis, patient counseling, and vaccine-safety monitoring without undermining clinically indicated immunization.