Increased Stroke Risk Following Herpes Zoster Infection and Protection With Zoster Vaccine

A comprehensive, updated systematic review and meta-analysis of epidemiologic evidence on the connection between herpes zoster infection and the risk of stroke

Stroke is a common worldwide cause of death and disability, resulting from an obstruction or reduction in blood flow to the brain. Research has demonstrated that systemic infection such as herpes zoster (HZ) / ophthalmicus herpes zoster (HZO) can potentially trigger stroke. This study includes an updated systematic review and meta-analysis of the epidemiologic data on the connection between HZ/HZO infection and the risk of stroke. A meticulous search of different database yielded 905 studies. Furthermore, an additional 14 studies from a previous meta-analysis were incorporated. Eligible studies underwent rigorous screening, resulting in 18 papers. Statistical analyses, including random/fixed effects models and subgroup analyses, were conducted to assess pooled relative risk (RR) and heterogeneity. The meta-analysis consisted of 5,505,885 participants and found a statistically significant association between HZ infection and the risk of stroke (pooled RR = 1.22, 95% confidence interval [CI] 1.12-1.34). The HZO infection showed a significantly higher overall pooled RR of 1.71 (95% CI 1.06-2.75), indicating a strong connection with the risk of stroke. Subgroup analysis revealed that the odds ratio might play a significant role in causing heterogeneity. Time since infection emerged as a crucial factor, with heightened stroke risk in the initial year post-HZ/HZO exposure, followed by a decline after the first year. Asian/Non-Asian studies demonstrated varied results in HZ/HZO patients. Meta-analysis reveals a significant HZ/HZO-stroke link. Subgroups highlight varied risks and warrant extended Asian/non-Asian patient investigation.

Herpes zoster in Belgium: a new solution to an old problem

Herpes zoster (HZ) is caused by reactivation of the varicella-zoster virus. The life-time risk of developing HZ is ~ 30%. Management of HZ can be challenging due to limited efficacy of oral antivirals on pain control, and neuropathic pain that may require aggressive management. Post-herpetic neuralgia (PHN) can cause substantial pain and occurs in up to one-quarter of patients with HZ. Up to 48,000 HZ cases are estimated to occur annually in Belgium, estimated to cost almost 7 million euros in treatment. The recombinant zoster vaccine (RZV, Shingrix, GSK) was approved in Europe in 2017. In 2022, the Belgian Superior Health Council recommended vaccination with RZV for immunocompetent adults aged ≥ 60 years, and immunocompromised patients aged ≥ 16 years, including those receiving immunosuppressive therapy, in particular Janus kinase inhibitors. RZV showed high age-independent efficacy in preventing HZ infection and in clinical trials that has since been confirmed in real-world effectiveness studies. In clinical trials, protection was sustained for at least 10 years after vaccination. As of 1 November 2023, RZV is reimbursed for three immunocompromised patient groups aged ≥ 18 years: malignancy treated in the past 5 years, HIV infection, and organ or haematological stem cell transplantation or are a transplant candidate. HZ is vaccine-preventable and RZV provides a highly effective tool for HZ prevention. While reimbursement for some at-risk groups is welcomed, reimbursement currently falls well short of Superior Health Council recommendations. Adult immunisation strategies should be promoted to achieve high vaccination coverage against HZ, contributing to healthy aging in Belgium.

The association of stroke with herpes zoster ophthalmicus

BACKGROUND/OBJECTIVES

Studies have reported an association between herpes zoster ophthalmicus (HZO) and stroke. We sought to validate this association with rigorous controls for both medical comorbidities and social factors using a nationwide U.S. administrative medical claims database.

SUBJECTS/METHODS

A two-step approach was taken: first a retrospective case-control study was performed, followed by a self-controlled case series (SCCS). For the case control study, cox proportional hazard regression with inverse proportional treatment weighting assessed the hazard for stroke. In the SCCS, incidence of stroke was compared prior to and after the diagnosis of HZO.

RESULTS

For the case-control study, 25,720 cases and 75,924 controls met our eligibility criteria. 1712 (6.7%) and 4544 (6.0%) strokes occurred in the case and control groups respectively, conferring an 18% increased risk of stroke in the observed 1-year post-HZO period (HR = 1.18, 95% CI: 1.12-1.25, p < 0.001). SCCS analysis showed the risk for stroke was highest in the month immediately after HZO episode compared to any other time range (1-30 days after, relative risk 1.58, p < 0.001) and even higher when assessing time more distal time points prior to the HZO diagnosis (days 1-30 after HZO diagnosis had RR = 1.69 (95% CI: 1.38-2.07) and RR = 1.93 (95% CI: 1.55-2.39) compared with days -120 to -91 and -150 to -121 prior to index, respectively (p < 0.001).

CONCLUSIONS

After accounting for stroke risk factors, our analysis confirms the association between HZO and stroke, with highest risk in the immediate month after an episode.

Varicella Zoster vaccination in hemodialysis patients: The state of the art

Varicella Zoster Virus (VZV) infection is a common childhood exanthematous disease, which in adults and immunocompromised people may result in severe neurologic complications. Up to one-third of infected subjects may have VZV clinical reactivation particularly if immunocompromised. Patients affected by end-stage renal disease on hemodialysis present immunodepression that contributes to their higher incidence of VZV infections and reactivation. While antiviral treatment in these patients shows low efficacy, the prevention of VZV through vaccination avoids the primary infection and the risk of reactivation. Two VZV vaccines are currently available: the live attenuate Zoster Vaccine (LZV) and a Recombinant Zoster Vaccine (RZV), with the latter appearing to provide greater efficacy. Given the higher incidence of VZV infection and reactivation, the lesser response to antivirals and the lower impact of VZ vaccine in hemodialysis patients in terms of side effects, a higher diffusion of VZV vaccination should be promoted by nephrologists in these patients in particular in those with future transplant opportunities.

Varicella-Zoster Virus Reactivation and Increased Vascular Risk in People Living with HIV: Data from a Retrospective Cohort Study

BACKGROUND

The increased vascular risk associated with varicella-zoster virus (VZV) reactivation is extensively established in the general population. This retrospective cohort study investigates whether this observation holds for People Living with HIV (PLWH), a group already confronting heightened cardiovascular risk.

METHODS

Among PLWH who initiated antiretroviral therapy (ART) at our center and have been under our care for >24 months since 1st January 2005, individuals with a history of herpes zoster (HZ) were identified, and their features were compared with those of PLWH with no history of HZ. The prevalence of ischemic events (deep venous thrombosis, stroke, and acute myocardial infarction) was calculated and compared using the chi-square test. An odds ratio (O.R.) and a 95% confidence interval (C.I.) for ischemic events following HZ were evaluated through univariate and multivariate logistic regression.

RESULTS

Overall, 45/581 PLWH reported HZ. Ischemic events followed HZ significantly more often than not (13% vs. 5%, p = 0.01). Positive serology for both VZV and HZ correlated with increased ischemic risk (O.R. 4.01, 95% C.I. 1.38-11.6, p = 0.01 and O.R. 3.14, 95% C.I. 1.12-7.68, p = 0.02, respectively), though chronic heart disease demonstrated stronger predictive value in multivariate analysis(O.R. 8.68, 95% C.I. 2.49-29.50, p = 0.001).

CONCLUSIONS

VZV potentially exacerbates vascular risk in PLWH, particularly in the presence of other predisposing factors. Further research is needed to confirm our data.

The Real-World Study of Immunogenicity and Safety of the Adjuvant Recombinant Vaccine against Varicella Zoster Virus in Patients with Immune-Mediated Inflammatory Diseases Treated with Janus Kinase Inhibitors

Background. The risk of herpes zoster reactivation is increased in immunocompromised patients, especially in those with immune-mediated inflammatory diseases (IMIDs) on Janus kinase inhibitor (JAKi) treatment. The recombinant subunit herpes zoster vaccine (RZV) is a non-live vaccine, recently approved for this subgroup of patients, which shows high rates of vaccine effectiveness, with few adverse effects reported in clinical trials. Purpose. The aim of this real-world study was to determine the immunogenicity and safety of RZV in IMID patients on JAKi treatment. Methods. The increase in the concentration of anti-gE antibody for varicella zoster virus post-vaccination, compared to the pre-vaccination concentration, was analyzed to test the humoral immune response. Adverse effects after the first and second vaccine doses were registered. Results. In total, 49 patients were analyzed, and a fourfold increase in antibody concentration was achieved in almost 40% of subjects, with only one serious local adverse effect. Discussion. The resulting immunogenicity was lower than that observed in clinical trials, probably due to the presence of immune disease and immunosuppressive treatment, and to the fact that this was a real-world study. No differences in response according to age, previous virus zoster reactivation, or concomitant treatments were found. Conclusions. RZV was well tolerated and reached the immune response objective in 40% of patients. These results reinforce the importance of including RZV vaccination for immunosuppressed patients. Real-world studies regarding vaccine effectiveness are still needed in order to gain a full understanding of the response to RZV in this group of patients.

Effects of herpes zoster vaccination and antiviral treatment on the risk of stroke: a systematic review and meta-analysis

Background

Evidence suggests that there is an increased risk of stroke after herpes zoster (HZ). However, reports on the effects of HZ vaccination (HZV) and antiviral treatment on stroke risk are inconsistent. Thus, we examined these associations in a meta-analysis.

Methods

To identify relevant studies, we searched three databases for articles published up to January 2023. Random-effect models were examined to determine overall pooled estimates and 95% confidence intervals (CIs).

Results

This review included 12 observational studies (six on HZV and seven on antiviral treatment). When comparing vaccinated and unvaccinated patients, vaccination was found to be associated with a lower risk of stroke (OR, 0.78; 95% CI 0.68-0.9; P = 0.001). A meta-analysis of self-controlled case series (SCCS) revealed evidence of a reduced OR in individuals who received the vaccine (OR, 1.14; 95% CI 0.94-1.37; P = 0.181) compared with unvaccinated individuals (OR, 1.36; 95% CI 1.15-1.61; P < 0.001). Compared with untreated patients, antiviral therapy was not associated with a reduced risk of stroke (OR, 1.13; 95% CI 0.94-1.36; P = 0.201). The meta-analysis of the SCCS showed no evidence of a reduced OR in individuals who received antiviral therapy (OR, 1.33; 95% CI 1.17-1.51; P < 0.001) compared to untreated individuals (OR, 1.45; 95% CI 1.25-1.69; P < 0.001).

Conclusions

This meta-analysis suggests that the HZV, but not antiviral treatment, decreases the odds of developing stroke.

Herpes zoster and long-term vascular risk: a retrospective cohort study

Herpes zoster (HZ) represents a serious health problem in the general population due to its abundance and complications. Stroke and acute myocardial infarction are well-documented short-term complications of HZ, primarily due to vasculopathy in the cerebral and coronary arteries. However, no major study to date has specifically demonstrated that HZ is a long-term risk factor for all Major Adverse Cardiac and Cerebrovascular Events (MACCE). A retrospective cohort study was conducted analyzing the association between HZ and MACCE. We compared HZ patients diagnosed between 2001 and 2018 and a matched control group. The model was stratified according to matched pairs and adjusted for age, socioeconomic status, history of dyslipidemia, and prior myocardial infarction (MI). Association between HZ exposure and stroke was assessed through a multivariable Cox regression analysis. The study included 41,930 patients, with 20,965 patients in each group. The risk of MACCE was 19% higher among HZ patients in the first year of follow up (P < 0.001). Antiviral treatment did not positively affect long-term survival among HZ patients (P < 0.001). These results suggest that HZ is a marker of long-term vascular risk. Additional studies will be needed to further evaluate this risk, the impact of HZ vaccination on such risk, and potential mitigation strategies.