Study: Primary COVID-19 Vaccines Found to Not Increase Risk of Herpes Zoster

Subgroup analyses suggest that a primary dose of the COVID-19 vaccine does not increase risk of herpes zoster infection, regardless of age, immunocompromised status, and type of vaccine administered.

A single or full primary dose of the COVID-19 vaccine was not associated with an increased risk of herpes zoster, also termed shingles, when stratifying age, immunocompromised status, and type of vaccine administered, according to study authors who recently published their findings in JAMA Network Open.

“COVID-19 vaccination was not found to be associated with a higher risk of herpes zoster compared with influenza vaccination in either the prepandemic or early pandemic periods,” wrote the study authors.

There were more diagnosed cases of herpes zoster after dose 1 of the COVID-19 vaccine compared to dose 2 (459 and 432, respectively)—however, patients aged 50 years and older, or immunocompromised, had an increased risk of herpes zoster following vaccination. Additionally, although more than 50% of herpes zoster infections were among women, with more than 70% of patients being White, the authors noted that neither suggest an association.

Herpes zoster is a dermatomal rash that leads to pain and can reduce quality of life. Caused by a reactivation of latent varicella zoster virus, some studies have suggested that doses 1 and 2 of the COVID-19 vaccine can increase risk of contracting herpes zoster.

While there is no established association, the ambiguity of data “has generated uncertainty among physicians,” study authors wrote. Further, many patients have expressed concern, which could be contributing to vaccine hesitancy, according to the authors.

During the analysis, the study authors noted that they used self-controlled risk interval (SCRI) to evaluate a possible association between increased risk of herpes zoster diagnosis and COVID-19 vaccination.

In the retrospective cohort study, researchers found health care claims data from Optum Labs Data Warehouse, identifying 2,039,854 patients who received a dose of the COVID-19 vaccine. Patients were assessed for herpes zoster after 30 days of receiving primary doses 1 or 2, or if they had an up-to-date record of dose 2.

Among participants, 1451 patients were diagnosed with herpes zoster in a risk or control interval. Additionally, the study authors noted that when looking at infected demographics, 606 (41.8%) were male, 99 (6.8%) were Asian, 80 (5.5%) were Black, 131 (9.0%) were Hispanic, 1026 (70.7%) were White, and 115 (7.9%) were of unknown race and/or ethnicity.

Further, the authors explained that the study contains limitations, such as outcome misclassification. Additionally, the study does not include patients with Medicare or Medicaid plans, or uninsured individuals, and the vaccine group underrepresents some demographic groups. Finally, the results may not be generalizable to all individuals who got the COVID-19 vaccine.

The COVID-19 vaccines have reduced mortality and morbidities of the SARS-CoV-2 infection, and available booster doses have kept immunizations up for millions. The vaccines are generally recognized as safe in clinical trials, but new multicenter trials are focusing on postvaccine safety, and current study authors suggest we continually monitor vaccine safety.

“This study…did not find an association between COVID-19 vaccination and an increased risk of herpes zoster infection,” study authors wrote. “It is possible that cases of herpes zoster after vaccination differ in disease course; however, further research is needed to assess this possibility.”

Reference

Akpandak, Idara, Miller, Claire, Sun, Yuwei, et al. Assessment of Herpes Zoster Risk Among Recipients of COVID-19 Vaccine. JAMA Netw Open. 2022;5(11):e2242240. doi:10.1001/jamanetworkopen.2022.42240