Acute Corneal Transplant Rejection; photophobia; Brow ache and decreased vision in the left eye; brow ache; This literature-non-study case was reported in a literature article and describes the occurrence of TRANSPLANT REJECTION (Acute Corneal Transplant Rejection) in a 77-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.   LITERATURE REFERENCE: Acute corneal transplant rejection after COVID-19 vaccination. Cornea. 2021;00(00)     The patient's past medical history included Keratoplasty (Received PKP with cataract extraction in the left eye 22 years previously for corneal edema secondary to amantadine usage for mild relapsing-remitting multiple sclerosis).   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 1. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 1. On an unknown date, the patient experienced TRANSPLANT REJECTION (Acute Corneal Transplant Rejection) (seriousness criterion medically significant), PHOTOPHOBIA (photophobia), VISUAL IMPAIRMENT (Brow ache and decreased vision in the left eye) and PAIN (brow ache). The patient was treated with PREDNISOLONE ACETATE at a dose of 1 percent, 5 times daily. At the time of the report, TRANSPLANT REJECTION (Acute Corneal Transplant Rejection), PHOTOPHOBIA (photophobia) and VISUAL IMPAIRMENT (Brow ache and decreased vision in the left eye) was resolving and PAIN (brow ache) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Slit-lamp examination: slitlamp examination showed mild conjunctival Slitlamp examination showed mild conjunctival hyperemia and injection, mild corneal edema, anterior chamber flare and cell, as well as numerous mixed KPs and decreased Slitlamp examination demonstrated reduced KPs and complete resolution of corneal edema as well as the anterior chamber cells and flare.. On an unknown date, Visual acuity tests: decreased BCVA was found to have declined to 20/60 and increased BCVA improved to 20/40.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered TRANSPLANT REJECTION (Acute Corneal Transplant Rejection), PHOTOPHOBIA (photophobia), VISUAL IMPAIRMENT (Brow ache and decreased vision in the left eye) and PAIN (brow ache) to be possibly related.    This case concern 4 out of 4 patients with prior keratoplasty developed presumed immunologic rejection after the mRNA-1273 vaccination for coronavirus 2 (SARS-CoV-2). Patient presented with endothelial rejection of the penetrating keratoplasty graft 2 weeks after the second vaccine dose. No previous graft rejection episodes occurred despite inconsistent use of topical corticosteroids. There was no history of COVID-19related illness or known exposure.  Patient experienced initial improvement with steroid treatment as well. These cases suggest acute corneal endothelial rejection may occur soon after either dose of the COVID-19 mRNA vaccine. Prompt initiation of aggressive topical steroid therapy may result in complete resolution of clinical signs and symptoms. Further studies are needed to elucidate the causal mechanism of corneal graft rejection after COVID-19 vaccination.  These cases suggest acute corneal endothelial rejection may occur soon after either dose of the COVID-19 mRNA vaccine. Prompt initiation of aggressive topical steroid therapy may result in complete resolution of clinical signs and symptoms. Further studies are needed to elucidate the causal mechanism of corneal graft rejection after COVID-19 vaccination.  Company Comment: This case concerns a  77 year-old, male subject  with clinical history of CORNEAL TRANSPLANT who experienced the unexpected event of TRANSPLANT REJECTION and other non-serious events. The event occurred one week after the second dose of [Spikevax]  The rechallenge is unknown as per no information is available at the time of the report. The benefit-risk relationship of the vaccine is not affected by this report   This case was linked to MOD-2021-349123, MOD-2021-353544, MOD-2021-353543 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 13-Oct-2021: Follow up received 14-Oct-2021. Received from team and contain  new information about patient identifiers.; Sender's Comments: This case concerns a  77 year-old, male subject  with clinical history of CORNEAL TRANSPLANT who experienced the unexpected event of TRANSPLANT REJECTION and other non-serious events. The event occurred one week after the second dose of [Spikevax]  The rechallenge is unknown as per no information is available at the time of the report. The benefit-risk relationship of the vaccine is not affected by this report