COVID-19 and vaccination against COVID-19 as possible trigger factors for the reactivation of human herpes viruses and development of herpetic eye diseases

The review summarizes current data on the impact of COVID-19 and vaccination against it on the reactivation of human herpes viruses (HHV) and the associated development of herpetic eye diseases. A cumulative assessment of the reactivation frequency of distinct HHVs in patients with COVID-19 is presented and it shows that many COVID-19 clinical manifestations can be caused by reactivation of different HHVs. The development of herpetic acute retinal necrosis (ARN) and keratitis is described, confirmed by the presence of one of the HHVs genome in intraocular fluids, corneal cells and by the effectiveness of antiherpetic drugs (valaciclovir, famciclovir). HHV eye diseases can occur during different periods of COVID-19: acute period, recovery stage, long-term period (chronic COVID-19). Systemic pathology, history of ophthalmoherpes, corticosteroids and immunomodulatory drugs intake contribute to the reactivation of HHV and the development of herpetic eye diseases against the background of coronavirus infection. Eye complications have been reported with different types of COVID-19 vaccines. Although eye diseases are recorded much less frequently than complications of other localizations, if incorrectly diagnosed they can lead to severe functional outcomes. Most often, eye pathology in vaccinated people (ARN, keratitis, relapses of herpetic keratitis) is caused by the varicellazoster virus, although other HHVs were also detected. Although the issue of continuing vaccination after a reaction to one of the vaccine doses is controversial, the presence of side effects requires a careful assessment of all the indications and contraindications for a particular person. At the moment, most authors believe that HHV reactivation with the uprise of herpetic eye disease in vaccinated individuals is rare, and that cause-and-effect relationship with vaccine introduction needs to be confirmed. Further multicenter studies involving control groups of unvaccinated individuals are needed to comparatively assess the effectiveness and safety of commercially available vaccines.