Results of a study published in Inflammatory Bowel Diseases shows that COVID-19 infection is associated with increased risk for herpes zoster (HZ) in patients with inflammatory bowel disease (IBD).

Researchers in Massachusetts conducted a retrospective cohort study from January 2020 to January 2023 to evaluate the risk for HZ in patients with IBD following COVID-19 infection. Eligible patients were adults with IBD (ulcerative colitis or Crohn disease). The researchers used 1:1 propensity score matching to assess the risk for HZ between patients with and without (controls) a history of laboratory-confirmed SARS-CoV-2 infection. Logistic regression was used to generate propensity scores, and the groups were matched by demographic characteristics, HZ risk factors, and IBD medications. All patients were receiving at least 1 IBD-related medication at the time of enrollment.

A total of 7912 patients were enrolled in the COVID-19 cohort and 59,066 in the control cohort in the pre-COVID-19 vaccine era, of whom the mean ages were 50.2 and 47.7 years, 60.1% and 52.1% were women, 12.6% and 9.7% were Black, and 61.1% and 61.6% had Crohn disease, respectively. Patients in the COVID-19 cohort had higher rates of comorbid conditions and autoimmune disorders, and 14.4% were hospitalized following COVID-19 diagnosis.

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During the pre-COVID-19 vaccine era, HZ occurred among 0.68% of patients in the COVID-19 cohort and 0.41% of those in the control cohort. After the researchers applied propensity score matching, the risk for HZ was increased among patients in the COVID-19 cohort compared with those in the control cohort (adjusted odds ratio [aOR], 3.49; 95% CI, 1.92-6.36).

Further analysis demonstrated that patients in the COVID-19 cohort who did (aOR, 6.26; 95% CI, 2.89-13.59) and did not (aOR, 2.57; 95% CI, 1.41-4.69) require hospitalization were both at increased risk for HZ when compared with those in the control cohort.

The researchers then assessed the risk for HZ in the post-COVID-19 vaccine era among propensity-score matched patients in the COVID-19 (n=10,027) and control (n=4984) cohorts. As observed in the prevaccine era, the between-group risk for HZ was higher for patients in the COVID-19 cohort, both overall (aOR, 3.04; 95% CI, 1.48-6.24) and among those who did (aOR, 6.50; 95% CI, 2.37-18.08) and did not (aOR, 3.13; 95% CI, 1.51-6.44) require hospitalization.

Of note, the risk for HZ among patients with IBD in the COVID-19 cohort was lower among those enrolled in the post- vs pre-COVID-19 vaccine era (aOR, 0.45; 95% CI, 0.27-0.76).

Study limitations include the possibility that patients enrolled during the COVID-19 pandemic were less willing to seek care. Other limitations include the inability to assess the risk for HZ by each IBD medication class and the potential effect of prior HZ diagnosis and HZ vaccination.

According to the researchers, “[G]iven the increased risk of HZ after SARS-CoV2 infection, patients should get the updated COVID-19 booster vaccine.”

Disclosures: Multiple study authors declared affiliations with pharmaceutical, biotech, and/or device companies. Please see the original reference for a full list of disclosures.


Desai A, Soni A, Hayney MS, et al. Increased risk of herpes zoster in adult patients with inflammatory bowel disease after SARS-CoV2 infection: a propensity-matched cohort studyInflamm Bowel Dis. Published online August 4, 2023. doi:10.1093/ibd/izad162

This article originally appeared on Infectious Disease Advisor