Increased Incidence of Giant Cell Arteritis After Introduction of a Live Varicella Zoster Virus Vaccine

BACKGROUND: Varicella zoster virus (VZV) has been associated with giant cell arteritis (GCA). The introduction of a live attenuated vaccine against this virus (ZVL) might have changed the incidence of GCA. METHODS: The incidence of GCA was retrospectively measured using 2 matched cohorts seen in a regional health system located in the Midwestern United States: ZVL recipients from the years 2007 through 2015 following the introduction of the vaccine and nonrecipients from the years 2000 through 2015. RESULTS: In the ZVL cohort, a significant increase of GCA was associated with clinical criteria alone for the diagnosis of GCA (hazard ratio [HR], 2.70; 95% CI, 1.48–4.45; P = .004). In addition, using only pathologically confirmed GCA, the same matched cohort comparison analysis also found that ZVL recipients were at significantly higher risk than those who did not receive ZVL (HR, 2.70; 95% CI, 1.48–4.95; P = .001). CONCLUSION: Using a matched cohort, retrospective comparison, ZVL was associated with an increased incidence of GCA.