Giant cell arteritis following varicella zoster vaccination

Background: Giant cell arteritis (GCA) is a form of large-vessel vasculitis affecting patients older than 50years old. Recent reports have suggested that the condition is caused by reactivation of varicella zoster virus (VZV). If that is indeed the case, a vaccine that prevents VZV reactivation should reduce the incidence of GCA. To further test that hypothesis, we assessed the incidence of GCA among patients older than 50years of age who were vaccinated against VZV and compared it to GCA incidence in the general population.
Methods: Using a centralized electronic medical database of the major medical insurer in Israel, Clalit Health Services (CHS), we have calculated the incidence of newly-diagnosed GCA patients in the general population, as well as the incidence of GCA among patients previously vaccinated against VZV between 1.1 2014-31.10.2016.
Results: The mean incidence of newly-diagnosed GCA among non-vaccinated patients older than 50years of age was 41.6/100,000/year, while the mean incidence of GCA among patients previously vaccinated against VZV in the same time period was 75.2/100,000/year (P=0.07).
Conclusions: These findings do not support the hypothesis that GCA is due to VZV reactivation.