Impact of herpes zoster vaccination on incident dementia: A retrospective study in two patient cohorts

• Published in: PloS one Vol. 16; no. 11; p. e0257405
• Main Authors: Scherrer, Jeffrey F., Salas, Joanne, Wiemken, Timothy L., Hoft, Daniel F., Jacobs, Christine, Morley, John E.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.11.2021; Public Library of Science (PLoS)
• Subjects: Age; Aged; Alzheimer's disease; Alzheimers disease; Biology and Life Sciences; Chronic obstructive pulmonary disease; Codes; Complications and side effects; Dementia; Dementia - epidemiology; Dementia - etiology; Dementia disorders; Female; Follow-Up Studies; Government programs; Health insurance; Health risk assessment; Health risks; Herpes viruses; Herpes zoster; Herpes Zoster - immunology; Herpes Zoster - prevention & control; Humans; Immune system; Immunology; Incidence; Infections; Infectious diseases; Internal medicine; Jacobs, John; Kidney diseases; Laboratories; Male; Medical records; Medicare; Medicine; Medicine and Health Sciences; Neuroprotection; Patients; Prevention; Proportional Hazards Models; Race; Retrospective Studies; Risk factors; Risk management; Risk reduction; Sensitivity analysis; Shingles (Disease); Social Sciences; Vaccination; Vaccines; Veterans Health Services; Viral infections; United States; St Louis Missouri; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0257405

Herpes zoster (HZ) infection increases dementia risk, but it is not known if herpes zoster vaccination is associated with lower risk for dementia. We determined if HZ vaccination, compared to no HZ vaccination, is associated with lower risk for incident dementia. Data was obtained from Veterans Health Affairs (VHA) medical records (10/1/2008-9/30/2019) with replication in MarketScan® commercial and Medicare claims (1/1/2009-12/31/2018). Eligible patients were ≥65 years of age and free of dementia for two years prior to baseline (VHA n = 136,016; MarketScan n = 172,790). Two index periods (either start of 2011 or 2012) were defined, where patients either had or did not have a HZ vaccination. Confounding was controlled with propensity scores and inverse probability of treatment weighting. Competing risk (VHA) and Cox proportional hazard (MarketScan) models estimated the association between HZ vaccination and incident dementia in all patients and in age (65-69, 70-74, ≥75) and race (White, Black, Other) sub-groups. Sensitivity analysis measured the association between HZ vaccination and incident Alzheimer's dementia (AD). HZ vaccination at index versus no HZ vaccination throughout follow-up. VHA patients mean age was 75.7 (SD±7.4) years, 4.0% were female, 91.2% white and 20.2% had HZ vaccination. MarketScan patients mean age was 69.9 (SD±5.7) years, 65.0% were female and 14.2% had HZ vaccination. In both cohorts, HZ vaccination compared with no vaccination, was significantly associated with lower dementia risk (VHA HR = 0.69; 95%CI: 0.67-0.72; MarketScan HR = 0.65; 95%CI:0.57-0.74). HZ vaccination was not related to dementia risk in MarketScan patients aged 65-69 years. No difference in HZ vaccination to dementia effects were found by race. HZ vaccination was associated with lower risk for AD. HZ vaccination is associated with reduced risk of dementia. Vaccination may provide nonspecific neuroprotection by training the immune system to limit damaging inflammation, or specific neuroprotection that prevents viral cytopathic effects.