Why carry out this study?

Herpes zoster (HZ) incidence is common in adults and can lead to substantial clinical and economic burden, particularly through complications such as postherpetic neuralgia (PHN); incidence appears to be increasing in many settings.

Evidence comparing incidence and burden between the general adult population and clinically increased-risk groups (including younger adults) is needed to inform vaccination prioritisation when resources are constrained.

We quantified HZ incidence and temporal trends (2015–2021) and assessed complications, healthcare resource utilisation and direct medical costs in the general adult population and among adults with increased-risk conditions.

What was learned from the study?

HZ incidence increased with age, was higher among adults with increased-risk conditions and showed an overall upward trend from 2015 to 2021.

Adults with increased-risk conditions and HZ-related complications had higher healthcare utilisation and greater direct medical costs, with PHN contributing disproportionately to burden.

These findings support risk-stratified prevention strategies and can help prioritise zoster vaccination towards groups most likely to benefit under budget constraints.