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

BACKGROUND: 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.

METHODS: 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).

RESULTS: 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.

CONCLUSIONS: 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.