Prevention of Herpes Zoster: A Focus on the Effectiveness and Safety of Herpes Zoster Vaccines

Herpes Zoster Recurrence: A Narrative Review of the Literature

INTRODUCTION

Herpes zoster (HZ; shingles) is a painful, cutaneous disease caused by reactivation of the varicella zoster virus, which causes varicella (chickenpox) typically during childhood. The considerable healthcare burden of HZ is relatively well documented, with approximately one in three individuals experiencing at least one episode during their lifetime, debilitating symptoms including neuropathic pain, and complications such as post-herpetic neuralgia, vision loss, and rarely, stroke, and increased severity in immunocompromised individuals. However, we are not aware of a comprehensive review of literature specifically examining the burden of HZ recurrence.

METHODS

We conducted a PubMed search (1 January 2003-2 February 2023) to assess available literature on the incidence, risk factors, and clinical features of HZ recurrence.

RESULTS

The incidence of HZ recurrence reported by the studies identified was wide ranging. Studies in general populations of immunocompetent or immunocompetent/immunosuppressed (mixed) populations with an initial HZ episode estimate that approximately 1.2-9.6% of individuals may experience HZ recurrence, with an incidence rate of 1.7-16.6 cases per 1000 person-years. HZ recurrence was reported in 0.0-18.2% of immunocompromised individuals with HZ, with an incidence rate of 17.0-55 cases per 1000 person-years. Incidence rates varied according to study design, follow-up, and study populations. Recognized risk factors for HZ recurrence include immunocompromised status, female sex, family history, and comorbidities such as diabetes. Other factors that may predispose individuals to recurrence include long-lasting pain after the initial HZ episode and the presence of herpes zoster ophthalmicus.

DISCUSSION

Our review underlines that following an initial HZ episode, individuals remain at risk of HZ recurrence, adding to the disease burden in a population. As HZ is preventable by vaccination, national HZ vaccination recommendations should include the need for and timing of vaccination in both immunocompetent and immunocompromised individuals who have a history of HZ.

Knowledge About the Herpes Zoster (HZ) Vaccine and Its Acceptance Among the Population in Al-Ahsa City in the Kingdom of Saudi Arabia

Introduction Herpes zoster (HZ), caused by the varicella-zoster virus (VZV), poses a public health concern in Saudi Arabia, with an increasing number of cases reported in recent years. This study aimed to assess the knowledge and acceptance of the herpes zoster vaccine among Saudi Arabian citizens in Al-Ahsa. Methodology A descriptive cross-sectional study was conducted using online surveys administered via social media platforms. The study was conducted in Al-Ahsa, a city located in the Eastern Province of Saudi Arabia. Al-Ahsa serves as a representative urban area within Saudi Arabia. Result The study found a high level of awareness and knowledge about the vaccine, with 78.2% of the participants having heard of herpes zoster. The majority considered the vaccine effective (89%) and believed it was available in Saudi Arabia (87%). However, the vaccination rate was only 8%. The study revealed varied opinions on the target population for vaccination, with 39.7% favoring immunocompromised patients and 38.1% choosing individuals above 50 years. The reasons for not being vaccinated included a lack of information (38.3%) and the belief of being in good health (37.3%). Conclusion The findings suggest a need for targeted educational campaigns to address misconceptions and promote vaccination, particularly among healthcare providers and the recommended target populations. Future research should explore barriers to vaccination to inform tailored interventions.

Vaccines for preventing herpes zoster in older adults

BACKGROUND

Herpes zoster, commonly known as shingles, is a neurocutaneous disease caused by the reactivation of the virus that causes varicella (chickenpox). After resolution of the varicella episode, the virus can remain latent in the sensitive dorsal ganglia of the spine. Years later, with declining immunity, the varicella zoster virus (VZV) can reactivate and cause herpes zoster, an extremely painful condition that can last many weeks or months and significantly compromise the quality of life of the affected person. The natural process of ageing is associated with a reduction in cellular immunity, and this predisposes older adults to herpes zoster. Vaccination with an attenuated form of the VZV activates specific T-cell production avoiding viral reactivation. Two types of herpes zoster vaccines are currently available. One of them is the single-dose live attenuated zoster vaccine (LZV), which contains the same live attenuated virus used in the chickenpox vaccine, but it has over 14-fold more plaque-forming units of the attenuated virus per dose. The other is the recombinant zoster vaccine (RZV) which does not contain the live attenuated virus, but rather a small fraction of the virus that cannot replicate but can boost immunogenicity. The recommended schedule for the RZV is two doses two months apart. This is an update of a Cochrane Review first published in 2010, and updated in 2012, 2016, and 2019.

OBJECTIVES

To evaluate the effectiveness and safety of vaccination for preventing herpes zoster in older adults.

SEARCH METHODS

For this 2022 update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL 2022, Issue 10), MEDLINE (1948 to October 2022), Embase (2010 to October 2022), CINAHL (1981 to October 2022), LILACS (1982 to October 2022), and three trial registries.

SELECTION CRITERIA

We included studies involving healthy older adults (mean age 60 years or older). We included randomised controlled trials (RCTs) or quasi-RCTs comparing zoster vaccine (any dose and potency) versus any other type of intervention (e.g. varicella vaccine, antiviral medication), placebo, or no intervention (no vaccine). Outcomes were cumulative incidence of herpes zoster, adverse events (death, serious adverse events, systemic reactions, or local reaction occurring at any time after vaccination), and dropouts.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included two new studies involving 1736 participants in this update. The review now includes a total of 26 studies involving 90,259 healthy older adults with a mean age of 63.7 years. Only three studies assessed the cumulative incidence of herpes zoster in groups that received vaccines versus placebo. Most studies were conducted in high-income countries in Europe and North America and included healthy Caucasians (understood to be white participants) aged 60 years or over with no immunosuppressive comorbidities. Two studies were conducted in Japan and one study was conducted in the Republic of Korea. Sixteen studies used LZV. Ten studies tested an RZV. The overall certainty of the evidence was moderate, which indicates that the intervention probably works. Most data for the primary outcome (cumulative incidence of herpes zoster) and secondary outcomes (adverse events and dropouts) came from studies that had a low risk of bias and included a large number of participants. The cumulative incidence of herpes zoster at up to three years of follow-up was lower in participants who received the LZV (one dose subcutaneously) than in those who received placebo (risk ratio (RR) 0.49, 95% confidence interval (CI) 0.43 to 0.56; risk difference (RD) 2%; number needed to treat for an additional beneficial outcome (NNTB) 50; moderate-certainty evidence) in the largest study, which included 38,546 participants. There were no differences between the vaccinated and placebo groups for serious adverse events (RR 1.08, 95% CI 0.95 to 1.21) or deaths (RR 1.01, 95% CI 0.92 to 1.11; moderate-certainty evidence). The vaccinated group had a higher cumulative incidence of one or more adverse events (RR 1.71, 95% CI 1.38 to 2.11; RD 23%; number needed to treat for an additional harmful outcome (NNTH) 4.3) and injection site adverse events (RR 3.73, 95% CI 1.93 to 7.21; RD 28%; NNTH 3.6; moderate-certainty evidence) of mild to moderate intensity. These data came from four studies with 6980 participants aged 60 years or older. Two studies (29,311 participants for safety evaluation and 22,022 participants for efficacy evaluation) compared RZV (two doses intramuscularly, two months apart) versus placebo. Participants who received the new vaccine had a lower cumulative incidence of herpes zoster at 3.2 years follow-up (RR 0.08, 95% CI 0.03 to 0.23; RD 3%; NNTB 33; moderate-certainty evidence), probably indicating a favourable profile of the intervention. There were no differences between the vaccinated and placebo groups in cumulative incidence of serious adverse events (RR 0.97, 95% CI 0.91 to 1.03) or deaths (RR 0.94, 95% CI 0.84 to 1.04; moderate-certainty evidence). The vaccinated group had a higher cumulative incidence of adverse events, any systemic symptom (RR 2.23, 95% CI 2.12 to 2.34; RD 33%; NNTH 3.0), and any local symptom (RR 6.89, 95% CI 6.37 to 7.45; RD 67%; NNTH 1.5). Although most participants reported that their symptoms were of mild to moderate intensity, the risk of dropouts (participants not returning for the second dose, two months after the first dose) was higher in the vaccine group than in the placebo group (RR 1.25, 95% CI 1.13 to 1.39; RD 1%; NNTH 100, moderate-certainty evidence). Only one study reported funding from a non-commercial source (a university research foundation). All other included studies received funding from pharmaceutical companies. We did not conduct subgroup and sensitivity analyses AUTHORS' CONCLUSIONS: LZV (single dose) and RZV (two doses) are probably effective in preventing shingles disease for at least three years. To date, there are no data to recommend revaccination after receiving the basic schedule for each type of vaccine. Both vaccines produce systemic and injection site adverse events of mild to moderate intensity. The conclusions did not change in relation to the previous version of the systematic review.

Hospitalization burden related to herpes zoster infection during the COVID-19 pandemic in Spain (2020-2021)

Varicella-Zoster Virus (VZV) belongs to the family Herpesviridae. Herpes zoster (HZ) is caused by reactivation of latent VZV. It is associated with risk factors such as immunosenescence, immunosuppressive pathologies and pharmacological treatments. Patients with these risk factors are more likely to be hospitalized. Increases in HZ hospitalizations have been reported in many countries in recent years. The objective of this study is to estimate hospitalization rates, mortality rates and costs due to HZ during the worst years of the COVID-19 pandemic in Spain (2020-2021). This is a descriptive study based on an analysis of information from the Minimum Basic Dataset and coded according to the Spanish version of the 10th International Classification of Diseases (ICD-10-CM). Hospitalization, mortality and case-fatality rates, and median length of hospitalization were calculated.. The hospitalization rate was 14.4 cases per 100,000 inhabitants, and the mortality rate was 1.3 cases per 100,000 inhabitants. Both increased considerably with age. In this time period, 92.3% of the registered cases were people over 50 years of age. Nevertheless, during the COVID-19 pandemic period, hospitalization rate decreased and the mortality rate increased from previous years. HZ hospitalization and mortality rates are relevant issues in the public health of older people. It is highly recommended to evaluate new vaccination strategies against VZV to include the HZ vaccine for health care for elderly people, as well as to reduce the disease burden and associated risk factors. The estimation of HZ disease hospitalization costs were €100,433,904.

The EURO-FORTA (Fit fOR The Aged) List Version 2: Consensus Validation of a Clinical Tool for Improved Pharmacotherapy in Older Adults

BACKGROUND

The aging of our societies leads to a higher prevalence of multimorbidity and therefore polypharmacy, which often results in inappropriate drug treatment. To address this issue, numerous listing approaches, such as the Fit fOR The Aged (FORTA) list have been developed. FORTA's positive impact on the quality of medications and relevant clinical outcomes has been shown. Based on new emerging evidence and experiences with the existing FORTA lists, we aimed to update the FORTA lists in several European countries/regions.

METHODS

Two-step Delphi consensus procedures were conducted in Poland, UK/Ireland, Italy, Spain, the Nordic countries, The Netherlands and France. The existing European FORTA lists served as survey proposals.

RESULTS

Thirty-two experts agreed to take part in this study (return rate: 96.9%). The country/region-specific overall consensus for all items and participants after the first round was > 90%. FORTA lists from six participating countries, plus the FORTA list for the German-speaking countries, were collated into the new EURO-FORTA List, which now contains 267 items aligned to 27 indications. Three items were added to the EURO-FORTA List, and no drugs were deleted. Eight FORTA items were relabeled, and 96.9% of the labels remained unchanged.

CONCLUSION

In this study, seven new country/region specific FORTA lists, as well as a new overarching EURO-FORTA List, were developed. An overall increase in the mean consensus coefficient and increases for all disease-specific mean consensus coefficients show a wider consensus among participants. The new lists have the potential to improve drug therapy in older people internationally.

Long-term risk of herpes zoster following COVID-19: A retrospective cohort study of 2 442 686 patients

The long-term risk of herpes zoster (HZ) after recovery from a SARS-CoV-2 infection is unclear. This retrospective cohort study assessed the risk of HZ in patients following a COVID-19 diagnosis. This retrospective, propensity score-matched cohort study was based on the multi-institutional research network TriNetX. The risk of incident HZ in patients with COVID-19 was compared with that of those not infected with SARS-CoV-2 during a 1-year follow-up period. Hazard ratios (HRs) and 95% confidence intervals (CIs) of HZ and its subtypes were calculated. This study identified 1 221 343 patients with and without COVID-19 diagnoses with matched baseline characteristics. During the 1-year follow-up period, patients with COVID-19 had a higher risk of HZ compared with those without COVID-19 (HR: 1.59; 95% CI: 1.49-1.69). In addition, compared with the control group patients, those with COVID-19 had a higher risk of HZ ophthalmicus (HR: 1.31; 95% CI: 1.01-1.71), disseminated zoster (HR: 2.80; 95% CI: 1.37-5.74), zoster with other complications (HR: 1.46; 95% CI: 1.18-1.79), and zoster without complications (HR: 1.66; 95% CI: 1.55-1.77). Kaplan-Meier curve analysis (log-rank p < 0.05) results indicated that the risk of HZ remained significantly higher in patients with COVID-19 compared with those without COVID-19. Finally, the higher risk of HZ in the COVID-19 cohort compared with that in the non-COVID-19 cohort remained consistent across subgroup analyses regardless of vaccine status, age, or sex. The risk of HZ within a 12-month follow-up period was significantly higher in patients who had recovered from COVID-19 compared with that in the control group. This result highlights the importance of carefully monitoring HZ in this population and suggests the potential benefit of the HZ vaccine for patients with COVID-19.