No Causal Effect of COVID-19 on Varicella-Zoster Infection, Herpes Zoster Progression, and Postherpetic Neuralgia: A...

Coronavirus disease (COVID-19) may trigger the reactivation of the latent varicella-zoster virus and may be a risk factor for herpes zoster (HZ). However, the causal relationship between COVID-19 and varicella-zoster infections remains controversial. This study aimed to estimate the causal inferences between COVID-19 and HZ.

This study used a two-sample Mendelian randomization (MR) design. The inverse variance-weighted method was used as the primary method and sensitivity analyses were conducted, including the MR-Egger regression, weighted median and weighted mode. We searched at https://gwas.mrcieu.ac.uk/ using the keywords "COVID-19" for exposure data and "zoster" for outcome datasets.

We got 26 COVID-19 datasets and five zoster datasets. We used 26 COVID-19 datasets as exposure data corresponding to each zoster dataset for the MR analysis. There were nine datasets of COVID-19 where the number of SNPs was fewer than three in the MR analysis of the risk of HZ, varicella zoster virus (VZV) glycoprotein E and I antibody levels, anti-VZV IgG seropositivity, and post-zoster neuralgia. In addition, there were 10 datasets of COVID-19 where the number of SNPs was less than three in the MR analysis of anti-VZV IgG levels. The results of the MR analysis showed that all p-values were greater than 0.05. Sensitivity analysis revealed no evidence of horizontal pleiotropy in most two sample MR analyses.

Our results indicate that there is no causal relationship between COVID-19 and varicella-zoster infection, HZ progression, and postherpetic neuralgia.