Impact of COVID-19 Infection and Vaccination on Herpes Zoster Ophthalmicus: A Prospective Analysis From the Zoster Eye Disease Study

Purpose: The aim of this study was to assess the interplay between 2 important viral infections and their management, herpes zoster ophthalmicus (HZO) and COVID-19. Methods: A subanalysis from the Zoster Eye Disease Study, a prospective randomized controlled study examining prophylactic valacyclovir in HZO, and data collected on COVID-19 vaccination and infection from July 2020 were evaluated. Participants were included if enrolled from January 1, 2019, ensuring that their 18-month follow-up overlapped with the COVID-19 pandemic. Recurrence was defined as new or worsening stromal keratitis without ulceration, endothelial keratitis, iritis, dendritiform epithelial keratitis, or stromal keratitis with ulceration requiring a substantial increase or recommencement of topical steroid therapy. Results: A total of 402 participants were included in the analysis. Attenuated zoster vaccination live was given to 35 (8.7%) and recombinant zoster vaccine to 40 (10.0%) before study commencement. No difference was observed in incidence or severity of COVID-19 infection in those with previous zoster vaccination, and no difference was observed in those treated with valacyclovir prophylaxis. COVID-19 infection occurred in 71 participants (17.7%) during the study period, and COVID-19 vaccination was received by 170 participants (42.3%). No association was observed between HZO recurrence and COVID-19 infection ( P = 0.39) or vaccination ( P = 0.75) during the 18-month follow-up. The study was powered to detect a hazard ratio of 1.19 for COVID-19 infection or vaccine-associated recurrence. Conclusions: No significant association was observed between zoster vaccination or valacyclovir use and COVID-19 incidence or severity. In addition, no significant increase in HZO recurrence was observed following COVID-19 infection or vaccination.