Impact of COVID-19 Vaccination on Varicella Zoster Virus Reactivation: A Case Control Study

Background: Herpes zoster (HZ) is a medical condition of a significant global impact, with millions of people affected and rising incidence. Some risk factors of this disease had been reported in previous literatures worldwide; however, studies that pool evidence to provide estimates of newly emerged risk have yet to be conducted, especially in the context of the current pandemic. Therefore, the purpose of this study is to examine the association between COVID-19 vaccination and the risk of developing HZ in Kuwait. Methods: Clinically diagnosed 186 HZ patients were enrolled, along with 186 controls (1:1) with matched age (± 5years), sex and nationality. Data from cases and controls was collected using a predesigned interview questionnaire. The data was analyzed using logistic regression. Results: Most of cases and controls were non-Kuwaiti (61.8%) and male (69.4%). About one fifth (19.4%) of HZ cases developed HZ following vaccination against COVID-19 within the study period (two months). Cases were more likely than controls to have had COVID-19 vaccination history (adjusted matched odds ratio (OR) = 4.87; 95 percent confidence interval (CI): 2.40–9.89; P<0.001). Vaccinated HZ cases experienced significantly more lateralization to the left side (χ2 = 12.146, P = 0.000). Conclusions: Vaccination with COVID-19 had significant statistical association with varicella zoster activation. Future studies may contemplate to verify the observed results.