The age- independent efficacy of HZ/su is of clinical inter- est, since the incidence and severity of herpes zoster are higher among older adults. HZ/su may thus provide a benefit to the population with the greatest medical need.2 In addition, the on- going ZOE-70 study (ClinicalTrials.gov number, NCT01165229), which includes adults who are 70 years of age or older and is being conducted at the same study centers as the ZOE-50 study, will provide an opportunity to assess vaccine ef- ficacy against postherpetic neuralgia and other complications of herpes zoster.