USA: A retrospective cohort study published in Clinical Infectious Diseases found that some younger adults with common chronic conditions may have a higher risk of herpes zoster (shingles) than older adults currently targeted for routine vaccination, suggesting a need to reconsider vaccination strategies in this population. Herpes zoster (HZ), commonly known as shingles, is typically associated with advancing age and immunocompromised states. Adjusted incidence rate ratios (aIRRs) were calculated, with predefined thresholds to determine whether risk in younger adults was comparable to or higher than that in older adults without underlying conditions. These findings indicate that factors beyond age, particularly comorbidities, play a key role in herpes zoster risk. Overall, the results highlight the combined influence of underlying health conditions on susceptibility to herpes zoster.