To the Editor: In their observational cohort study of herpes zoster vaccine, Dr Tseng and colleagues reported that vaccination was associated with a 55% reduction in zoster incidence across all ages.1 Older patients have higher rates of zoster and should benefit most from vaccination, but because fewer than 7% of patients enrolled in the Shingles Prevention Study (SPS) were 80 years and older,2 the benefit of the vaccine in this age group remained uncertain. At first glance, the study by Tseng et al, which included almost 6000 vaccinated elderly patients, appeared reassuring.
Rothberg MB, Smith KJ. Herpes Zoster Vaccine and Older Adults. JAMA. 2011;305(14):1410-1411. doi:10.1001/jama.2011.422