An Association Between Herpes Zoster Vaccination and Stroke Reduction Among Elderly Individuals

Herpes zoster (HZ, shingles) affects individuals (60+ years) by reactivation of varicella virus from primary infection. Approximately one-third of the general population will develop HZ and are at increased risk of stroke. Our objective was describing possible associations between self-reported HZ vaccination and stroke with the Centers for Disease Control and Prevention's Behavioral Risk Factors Surveillance System, a cross-sectional nationwide telephone survey. Non-institutionalized U.S. adults answered items concerning health risk behaviors. 2014 survey data were from 265,568 adults 50-79 years old. Multivariable Cox regressions adjusted for standard demographics, body mass index, and coronary heart disease showed that HZ-vaccinated individuals had lower risk of reporting stroke those not vaccinated (hazard ratio [HR] = 1.73). After stratification of participants into six 5-year age groups, adjusted weighted binary logistic regressions were conducted for each age group with stroke as outcome. The HZ-vaccinated group aged 65-69 years reported stroke approximately 50% less than those unvaccinated (adjusted Odds Ratio [aOR] = 1.51; 99% confidence interval [CI]:1.21,1.88). Secondary analyses indicated that this benefit was among HZ-vaccinated whites (aOR = 1.6, 95%CI:1.4,2.0), but not African Americans or Hispanics. These possible protective effects are not detected 10 years after recommended vaccine uptake. Limitations include not following participants longitudinally and that time between stroke and vaccination could not be determined.