Transient Increased Risk of Shingles Post-Shingrix Vaccination: Self-Controlled Case-Series Analysis.

Abstract

Following the introduction of a funded recombinant shingles vaccine (RZV; Shingrix, GlaxoSmithKline) vaccination program in adults aged ≥65 years in Australia, clinician reports of shingles presentations shortly after vaccination emerged. We investigated whether there was an increase in shingles risk immediately post-RZV vaccination in southeastern Australia. Two independent datasets-a general practice dataset and a statewide linked dataset-were analyzed separately using self-controlled case series (SCCS) analyses with 21 days postvaccination as the risk window. The observation period was 1 January 2023 to 30 April 2025. Adults ≥18 years were included, with analyses stratified by age (<65 and ≥65 years) and sex. We calculated the rate of incident shingles in time periods relative to vaccination, along with attributable risk and the risk of postherpetic neuralgia (PHN). The primary care SCCS analysis found an 11-fold increase (relative incidence, 10.96; 95% CI, 10.34-11.62; P < .0001) in shingles presentations within 21 days post-dose 1 of RZV vaccination in adults ≥65 in the general practice dataset only. No increase was detected in younger adults. Following dose 2, the risk of shingles presentations was reduced in all age groups. Vaccine recipients had a 73% reduction in shingles following 2 doses. PHN risk was not increased. There is a transient increase in shingles presentations shortly after dose 1 of RZV vaccination in adults ≥65 years; however, these cases are likely to be mild and there is clear evidence of vaccine effectiveness after the completion of 2 doses.