Varicella-Zoster virus reactivation following severe acute respiratory syndrome coronavirus 2 vaccination or infection: New insights

Why carry out this study?.•People vaccinated against SARS-CoV-2 are daily increasing, and several cases of varicella zoster virus reactivation have been reported.•The real extend of reactivation risk has not been still elucidated.What was learned from the study?.•Varicella zoster virus reactivation among SARS-CoV-2 vaccinated or infected adults predominantly was a mild herpes zoster rash. Near 90% were non-serious. No pneumonia or death was reported.•The manifestations appeared predominantly within 10 days following the first dose or infection.•Our findings support that COVID-19 vaccination is safe and remains strongly recommended. Varicella zoster virus (VZV) reactivation has been reported following vaccination for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the real extent remains unknown. We conducted a systematic review to summarize evidence of VZV reactivation or infection following SARS-CoV-2 vaccination. Episodes after coronavirus disease-2019 (COVID-19) were also identified. Related articles were identified in PubMed and EMBASE databases till December 31, 2021 using the terms “varicella zoster” and “COVID-19″. PROSPERO Register Number: CRD42021289399. The search revealed 314 articles, of which 55 met the inclusion criteria. VZV manifestations were documented in 179 (82.1%) subjects following SARS-CoV-2 vaccination and in 39 (17.9%) patients with COVID-19. Among the vaccinated, median (IQR) age was 56.5 (42–70) years, and 56.8% were female. Twenty-one (16.8%) were immunosuppressed. The median (IQR) latency time after vaccination was 6 (3–10) days, and 84.4% received mRNA vaccines. VZV reactivation occurred following a first dose (68.2%), a second dose (12.8%) or a booster (0.6%). The most important VZV manifestation was dermatome herpes zoster rash, which accounted for 86.4% of events in vaccinated subjects. Twenty patients (11.3%) presented serious VZV events after vaccination, with Herpes Zoster ophthalmicus (5.6%) and post-herpetic neuralgia (3.4%) predominating. No VZV pneumonia or deaths were recorded. Antiviral prescriptions were made in 96.2% of vaccinated subjects. No significant differences between vaccinated and infected subjects were found. This study indicates that the occurrence of VZV reactivation is clinically relevant. However, our findings suggest that COVID-19 vaccination is safe, and remains strongly recommended.