The potential association between herpes zoster and COVID-19 vaccination

Little is known about the dermatological manifestations associated with COVID-19 vaccines. The aim of the study was to determine how many cases of herpes zoster (HZ) occurred after COVID-19 vaccination and to see if there was a possible link.

A retrospective cohort study was performed by archive scan between 2016 and 2020, and between January 2021 and January 2022. Patients diagnosed with HZ were enrolled and their demographic and medical history including age, sex, previous systemic disease, history of COVID-19 vaccination prior to HZ symptom onset, COVID-19 vaccine type as mRNA or inactive, time to HZ onset after vaccination, and number of COVID-19 vaccines before HZ symptom onset were recorded.

The average annual number of HZ cases from 2016 to 2020 was 271, but the number of HZ cases in 2021 was 338, reflecting an increase. The number of HZ patients with a known history of COVID-19 vaccination in 2021 was 117 and their mean age was 57.6 ± 14.2 years. Females were 59.8% (n = 70) and 28.2% (n = 33) had chronic diseases. A positive history of COVID-19 vaccination was present in 35.9% (n = 42) of HZ patients, 11.1% (n = 13) had received mRNA vaccines and 24.8% (n = 29) had received inactive COVID-19 vaccine. Mean time to HZ after COVID-19 vaccination was 24.6 ± 16.3 days.

An important finding of this study is the high rate (35.9%) of COVID-19 vaccination among people diagnosed with HZ. As COVID-19 vaccination may be associated with reactivation of varicella zoster virus, the vaccination history should be obtained in HZ patients.