Herpes Zoster Keratitis; Corneal folds; This case was reported in a literature article and described the occurrence of herpes zoster keratitis in a 75-year-old female patient who received Herpes zoster (Shingrix) for prophylaxis.   The patient's past medical history included ophthalmic herpes zoster (in right eye in 2013 and experienced a reactivation while on fluorometholone in 2018), conjunctival injection, punctate epithelial erosion (without dentrites), corneal edema (moderate inferior), corneal stromal opacity, corneal thinning and irregular astigmatism. Previously administered products included Prednisolone (a prolonged prednisolone taper, was treated with prednisolone 1% three times daily to the right eye then tapered to a maintenance dosage of twice weekly), fluorometholone (transitioned from a prolonged prednisolone taperi to fluorometholone twice weekly as a maintenance dose) and valacyclovir (orally 1,000 mg three times daily). Concurrent medical conditions included pseudophakia (with a posterior chamber intraocular lens) and glaucoma (controlled on latanoprost 0.005% and timolol 0.5% in both eyes). Concomitant products included prednisolone and latanoprost and timolol.   In January 2021, the patient received the 1st dose of Shingrix. On an unknown date, less than 3 weeks after receiving Shingrix, the patient experienced herpes zoster keratitis (serious criteria GSK medically significant) and corneal edema. The patient was treated with valaciclovir hydrochloride (Valtrex). On an unknown date, the outcome of the herpes zoster keratitis and corneal edema were recovered/resolved.   The reporter considered the herpes zoster keratitis and corneal edema to be related to Shingrix.     Additional Information: GSK Receipt Date: 31-Aug-2022 Author's comment: The patient first developed Herpes Zoster Ophthalmicus (HZO) keratitis in her right eye in 2013. The patient underwent a prolonged prednisolone taper and was eventually transitioned to fluorometholone twice weekly as a maintenance dose. In 2018, the patient experienced a reactivation while on fluorometholone, presenting with conjunctival injection, punctate epithelial erosions without dendrites, moderate inferior corneal edema and stromal haze. The patient was treated with predisolone 1% three times daily to the right eye and oral valacyclovir 1,000 mg three times daily. Two weeks later, the symptoms had completely resolved; the valacyclovir was discontinued, and prednisolone 1% was tapered to a maintenance dosage of twice weekly, which the patient continued to take reliably. The patient was examined approximately every 3-6 months without evidence of disease reactivation. On baseline examination in November 2020 of her right eye, her visual acuity was 20/150, pinhole to 20/70 with spectacle correction. The patient had a central stromal opacity with cornea thinning causing irregular astigmatism. The patient's pachymetry reading was 424 µ. The patient was pseudophakic with a posterior chamber intraocular lens. The fundus exam was unremarkable. The patient had glaucoma, controlled on latanoprost 0.005% and timolol 0.5% in both eyes. In January 2021, the patient received her first dose of the Shingrix vaccine. Two and a half weeks later, the patient was noted by her glaucoma specialist on a routine clinic visit to have a decreased visual acuity of 20/500 with corneal folds in her right eye, which was suspicious for HZO keratitis reactivation. The patient did not have any recent changes in her glaucoma medications. The patient was started on oral valacyclovir 1,000 mg twice daily. A month later, the corneal edema persisted, and her oral valacyclovir was increased to three times daily and prednisolone changed from 1 drop to the right eye twice weekly to three times daily. A week later, her corneal edema was much improved, and the valacyclovir dose was decreased to 1,000 mg daily along with a slow taper of the prednisolone 1%. A month later, the patient's symptoms had completely resolved, and her visual acuity returned to a baseline of 20/100 pinhole to 20/80 with no corneal edema on exam. Prednisolone 1% was tapered to her baseline of twice weekly over a 6-month period and valacyclovir was discontinued. "For inactivated vaccines such as Herpes zoster subunit vaccine (HZ/Su), the mechanism was more puzzling; one hypothesis was that one or more adjuvants contained in the vaccines can create an autoinflammatory response, which might either lead to or pose as HZO reactivation. The HZ/su vaccine was not listed as containing aluminum salts, although it did contain a lipid formulation which could be another possible culprit. Another possible explanation was a general upregulated immune response to the vaccine, causing inflammation of the cornea as was observed in herpes zoster keratitis. In our patient, reactivation of herpes zoster keratitis occurred a few weeks following the HZ/su vaccine. Fortunately, the patient made a complete recovery following treatment with prednisolone 1% three times a day and Valtrex 1,000 mg three times a day. Vaccine-associated adverse events such as disease reactivation are uncommon and difficult to prove. Although our patient's keratitis could be coincidental or even related to her glaucoma medications, reporting of possible correlations between HZ/su vaccine administration and HZO reactivation to public health institutions, was imperative for accurately understanding the risks associated with certain vaccines and to provide new information that could help elucidate the etiology of these responses." Additional Supportive Information: The article corresponding to this case is not available for regulatory submission due to copyright restriction.