Could Herpes Zoster Signal Post-COVID Immune Dysfunction?

Researchers analyzing health records from more than 110,000 COVID-19 survivors found that people who later experienced herpes zoster reactivation were more likely to develop certain neurological conditions, including Bell’s palsy, Guillain-Barré syndrome (GBS), and myasthenia gravis (MG), during the following three years. 

The timing of these conditions differed. Bell’s palsy tended to appear relatively soon after herpes zoster reactivation, while Guillain-Barré syndrome and myasthenia gravis were more likely to emerge later, often more than a year afterward. 

The researchers suggest that herpes zoster reactivation may reflect lingering immune dysregulation following COVID-19 infection. They propose that some neurological complications may result from direct effects on nerve tissue, while others could involve longer-term immune-mediated processes. 

Because the study was observational, it cannot determine whether herpes zoster reactivation directly causes these conditions. However, the findings add to growing evidence that COVID-19 may have lasting effects on immune and neurological health in some individuals.

Citation

Cheng YC, Lu CL, Wang J, Hou YC, Lu KC. Association Between Post-COVID-19 Herpes Zoster Reactivation and Peripheral Nervous System Disorders: Multinational Real-World Evidence from TriNetX. Int J Med Sci 2026; 23(6):2006-2015. doi:10.7150/ijms.127617. https://www.medsci.org/v23p2006.htm