The Epidemiology and Prevention of Herpes Zoster

Vaccines for the Elderly and Vaccination Programs in Europe and the United States

The share of the elderly population is growing worldwide as life expectancy increases. Immunosenescence and comorbidities increase infectious diseases' morbidity and mortality in older adults. Here, we aimed to summarize the latest findings on vaccines for the elderly against herpes zoster, influenza, respiratory syncytial virus (RSV), COVID-19, and pneumococcal disease and to examine vaccine recommendation differences for this age group in Europe and the United States. PubMed was searched using the keywords "elders" and "vaccine" alongside the disease/pathogen in question and paraphrased or synonymous terms. Vaccine recommendations were also sought in the European and US Centers for Disease Control and Prevention databases. Improved vaccines, tailored for the elderly, mainly by using novel adjuvants or by increasing antigen concentration, are now available. Significant differences exist between immunization policies, especially between European countries, in terms of the recipient's age, number of doses, vaccination schedule, and implementation (mandatory or recommended). Understanding the factors that influence the immune response to vaccination in the elderly may help to design vaccines that offer long-term protection for this vulnerable age group. A consensus-based strategy in Europe could help to fill the gaps in immunization policy in the elderly, particularly regarding vaccination against RSV and pneumococcus.

Factors influencing series completion rates of recombinant herpes zoster vaccine in the United States: A retrospective pharmacy and medical claims analysis

BACKGROUND/OBJECTIVES

Vaccination against herpes zoster (HZ) is an effective strategy in protecting the population against consequences of varicella zoster virus reactivation. Optimal immunogenicity with recombinant zoster vaccine (RZV) relies on completion of the 2-dose series within 2-6 months from the first dose. The objectives of this study were to estimate RZV completion rates and adherence with the recommended administration schedule in the general United States population aged at least 50 years and to evaluate factors influencing completion rates.

METHODS

Longitudinal, open-source pharmacy and medical claims databases were analyzed for adults aged at least 50 years with a first RZV prescription filled between October 2017 and September 2019. The data were linked to Experian Marketing Services Consumer View data to obtain information regarding race. Completion rates and adherence were calculated overall and stratified according to claim source, age class, sex, and payer type. Logistic regression models were built for each subpopulation of interest to identify factors correlating with completion rates.

RESULTS

Overall, cumulative completion rates were 70.41% and 81.80% at 6 and 12 months, respectively. Median time to second dose was approximately 4 months (4.08-5.13 months) and adherence 67.62%. Completion rates were lower in the medical claims database compared with the pharmacy claims database (48.98% vs. 73.23% at 6 months). Regression models confirmed that pharmacy claim was an independent factor for higher completion rates, while African American race and Medicaid status were associated with lower completion rates. Most comorbidities, including chronic obstructive pulmonary disease and type 2 diabetes mellitus, were associated with lower completion rates.

CONCLUSION

Pharmacists contribute substantially to the overall high RZV completion rates in the United States. However, completion rates can be improved, especially in people receiving their first RZV dose at a physician's office. Future strategies should aim at lowering barriers to completing vaccination series in African Americans, Medicaid beneficiaries, and people with comorbidities.

Acupuncture for improving a case of widespread herpes zoster after non-Hodgkin's lymphoma chemotherapy

BACKGROUND

Herpes zoster presents as clustered blisters on one side of the body, accompanied by nerve pain. This is caused by reactivation of the varicella zoster virus, and it occurs primarily in people with weakened immunity. Tumor and chemotherapy drugs can impair the patient's immune function, induce herpes zoster and prolong the course of disease.In these patients, skin changes can last for months and blisters can recur and cause serious complications such as postherpetic neuralgia.Acupuncture is a common alternative therapy for herpes zoster in East Asia.

CASE PRESENTATION

We report a case of an elderly male patient with widespread herpes zoster in the trunk after non-Hodgkin's lymphoma chemotherapy. The patient had received conventional treatment with valaciclovir and mecobalamin within 24 hours of symptom onset. Because neither the clustered blisters nor the nerve pain were improved a week later, acupuncture and related techniques were applied. These included electro-acupuncture, surrounding acupuncture, fire acupuncture, and cupping. The patient recovered 20 days after the herpes zoster attack, and there were no adverse reactions during the treatment process.

CONCLUSIONS

This case suggests that acupuncture and related techniques are effective interventions for this condition.This case report is innovative because it shows that acupuncture as an adjuvant treatment can improve the skin lesions in patients with HZ after tumour chemotherapy, relieve pain, and shorten the course of HZ.

Early impact of the Australian national shingles vaccination program with the herpes zoster live attenuated vaccine

Herpes zoster (shingles) is a painful condition resulting from reactivation of latent varicella zoster virus (VZV). The Australian National Shingles Vaccination Program (commenced November 2016) provides free herpes zoster vaccination for eligible adults aged 70 years, with a 5-year catch-up program (until October 2021) for adults aged 71-79 years. Patterns and impact of the program were evaluated by analysis of vaccine distribution and delivery data and specific antiviral prescription data from the Pharmaceutical Benefits Scheme. During the first 2 years, uptake of funded live attenuated shingles vaccine ZOSTAVAX® (Zoster Virus Vaccine Live; ZVL) was high across the ongoing and catch-up programs. Before program implementation (2006-2016), herpes zoster coded antiviral prescription rates increased by 2.2% per year (95% CI: 1.5, 2.9) in the 70-79 years age group. In the two years since program launch, herpes zoster antiviral prescription rates declined substantially in this age group, by an average of 13.6% per year (95% CI: 1.5, 24.2). These results indicate that the National Shingles Vaccination Program has been highly successful in vaccinating a considerable proportion of Australian adults aged 70-79 years against herpes zoster and suggest that vaccine uptake was associated with decreased incidence of herpes zoster.

Varicella-zoster meningitis in an immunocompetent young man presenting with a painless erythematous rash

A 32-year-old man presented with a 7-day history of generalised headache, intermittent fever, emesis and diarrhoea. Four days after symptom onset, he developed a vesicular rash on his medial left thigh, without associated pain, paraesthesia or pruritus. He had no significant past medical history, and no HIV risk factors. He was presumed to have enteroviral meningitis and was commenced on supportive therapy. Lumbar puncture was performed and cerebrospinal fluid (CSF) analysis revealed a lymphocytic pleocytosis. While awaiting CSF serology, the formation of a new vesicle was noted at the site of the rash and was swabbed. Results for both the CSF and vesicle swab returned positive for varicella-zoster virus (VZV) confirming concurrent VZV meningitis with atypical painless herpes zoster in a young immunocompetent patient. He was initiated on intravenous acyclovir and made a full recovery after 2 weeks of treatment.

Evaluation of Varicella-zoster virus-specific cell-mediated immunity by interferon-γ Enzyme-Linked Immunosorbent Assay in adults ≥50 years of age administered a herpes zoster vaccine

Varicella-zoster virus (VZV)-specific cell-mediated immunity (CMI) is critical for preventing and controlling the onset of herpes zoster (HZ). To assess VZV CMI, an interferon-γ (IFN-γ) enzyme-linked immunosorbent assay (ELISA) was validated by examining the influence of VZV-specific antigen content, incubation time, and interval from whole blood collection on the assay. In phase II clinical trial, VZV-specific CMI in adults ≥50 years of age administered an HZ vaccine were evaluated by IFN-γ ELISA, as determined by measuring IFN-γ production in the whole blood in response to stimulation with ultraviolet light-inactivated VZV. The VZV-specific IFN-γ levels varied among individuals from prevaccination (baseline) to 6 weeks postvaccination. In most subjects, VZV-specific CMI was increased at 6 weeks postvaccination. The HZ vaccine elicited a significant increase in the VZV-specific CMI response as measured by ELISA; the geometric mean fold-rises from baseline to 6 weeks postvaccination were 3.50, 4.22, and 5.24 in the 4.3, 4.7, and 4.9 log plaque-forming unit vaccine groups, respectively, which was significantly higher than in the placebo group (P < 0.05). These results indicate that vaccination enhances the VZV-specific CMI responses in subjects; IFN-γ ELISA is an effective method for evaluating the CMI response and may be useful for identifying individuals at a high risk of HZ infection.

Epidemiology, treatment and prevention of herpes zoster: A comprehensive review

Herpes zoster is a major health burden that can affect individuals of any age. It is seen more commonly among individuals aged ≥50 years, those with immunocompromised status, and those on immunosuppressant drugs. It is caused by a reactivation of varicella zoster virus infection. Cell-mediated immunity plays a role in this reactivation. Fever, pain, and itch are common symptoms before the onset of rash. Post-herpetic neuralgia is the most common complication associated with herpes zoster. Risk factors and complications associated with herpes zoster depend on the age, immune status, and the time of initializing treatment. Routine vaccination for individuals over 60 years has shown considerable effect in terms of reducing the incidence of herpes zoster and post-herpetic neuralgia. Treatment with antiviral drugs and analgesics within 72 hours of rash onset has been shown to reduce severity and complications associated with herpes zoster and post-herpetic neuralgia. This study mainly focuses on herpes zoster using articles and reviews from PubMed, Embase, Cochrane library, and a manual search from Google Scholar. We cover the incidence of herpes zoster, gender distribution, seasonal and regional distribution of herpes zoster, incidence of herpes zoster among immunocompromised individuals, incidence of post-herpetic neuralgia following a zoster infection, complications, management, and prevention of herpes zoster and post-herpetic neuralgia.

Inequalities in zoster disease burden: a population-based cohort study to identify social determinants using linked data from the U.K. Clinical Practice Research Datalink

BACKGROUND

Zoster vaccination was introduced in England in 2013, where tackling health inequalities is a statutory requirement. However, specific population groups with higher zoster burden remain largely unidentified.

OBJECTIVES

To evaluate health inequalities in zoster disease burden prior to zoster vaccine introduction in England.

METHODS

This population-based cohort study used anonymized U.K. primary care data linked to hospitalization and deprivation data. Individuals aged ≥ 65 years without prior zoster history (N = 862 470) were followed from 1 September 2003 to 31 August 2013. Poisson regression was used to obtain adjusted rate ratios (ARRs) for the association of sociodemographic factors (ethnicity, immigration status, individuals' area-level deprivation, care home residence, living arrangements) with first zoster episode. Possible mediation by comorbidities and immunosuppressive medications was also assessed.

RESULTS

There were 37 014 first zoster episodes, with an incidence of 8·79 [95% confidence interval (CI) 8·70-8·88] per 1000 person-years at risk. In multivariable analyses, factors associated with higher zoster rates included care home residence (10% higher vs. those not in care homes), being a woman (16% higher vs. men), nonimmigrants (~30% higher than immigrants) and white ethnicity (for example, twice the rate compared with those of black ethnicity). Zoster incidence decreased slightly with increasing deprivation (ARR most vs. least deprived 0·96 (95% CI 0·92-0·99) and among those living alone (ARR 0·96, 95% CI 0·94-0·98). Mediating variables made little difference to the ARR of social factors but were themselves associated with increased zoster burden (ARR varied from 1·11 to 3·84).

CONCLUSIONS

The burden of zoster was higher in specific sociodemographic groups. Further study is needed to ascertain whether these individuals are attending for zoster vaccination.

Effectiveness of herpes zoster vaccination in an older United Kingdom population

BACKGROUND

Vaccination against herpes zoster was introduced in the United Kingdom in 2013 for individuals aged 70 years, with a phased catch-up campaign for 71-79 year olds. Vaccine introduction has resulted in a marked fall in incident herpes zoster and in post-herpetic neuralgia (PHN), but formal evaluation of vaccine effectiveness is needed.

METHODS

In a population-based cohort study of older individuals born between 1933 and 1946, we used linked UK anonymised primary care health records for the first three years of the vaccination programme (01/09/2013-31/08/2016) and multivariable Poisson regression to obtain incidence rates and vaccine effectiveness (VE) against zoster and PHN.

RESULTS

Among 516,547 individuals, 21% were vaccinated. Incidence of zoster was 3.15/1000 person-years in vaccinees and 8.80/1000 person-years in unvaccinated individuals. After adjustment, VE was 64% (95%CI = 60-68%) against incident zoster and 81% (95%CI = 61-91%) against PHN, with very similar VE estimates in the routine and catch-up cohorts. VE against zoster was lower in those with a previous history of zoster: 47% (95%CI = 31-58%) versus 64% (95%CI = 60-68%) in those without previous zoster. There was evidence of waning VE over time, from 69% (95%CI = 65-74%) in the first year after vaccination to 45% (95%CI = 29-57%) by the third year.

CONCLUSION

This first formal assessment of VE in the UK zoster vaccination programme demonstrates good effectiveness of zoster vaccine, and very good protection against PHN. The findings provide evidence that VE is similar across the age groups targeted for vaccination in the UK, and on duration of protection of the vaccine in public health use. The study provides key information for decision-makers about the future direction of UK zoster vaccination programme, indicating that the live zoster vaccine may be more cost-effective than estimated previously. It also supports efforts to communicate the benefits of zoster vaccination to address the declining coverage observed across the UK.

Varicella zoster virus-associated morbidity and mortality in Africa - a systematic review

BACKGROUND

Varicella zoster virus (VZV) causes varicella and herpes zoster. These vaccine preventable diseases are common globally. Most available data on VZV epidemiology are from industrialised temperate countries and cannot be used to guide decisions on the immunization policy against VZV in Africa. This systematic review aims to review the published data on VZV morbidity and mortality in Africa.

METHODS

All published studies conducted in Africa from 1974 to 2015 were eligible. Eligible studies must have reported any VZV epidemiological measure (incidence, prevalence, hospitalization rate and mortality rate). For inclusion in the review, studies must have used a defined VZV case definition, be it clinical or laboratory-based.

RESULTS

Twenty articles from 13 African countries were included in the review. Most included studies were cross-sectional, conducted on hospitalized patients, and half of the studies used varying serological methods for diagnosis. VZV seroprevalence was very high among adults. Limited data on VZV seroprevalence in children showed very low seropositivity to anti-VZV antibodies. Co-morbidity with VZV was common.

CONCLUSION

There is lack of quality data that could be used to develop VZV control programmes, including vaccination, in Africa.

TRIAL REGISTRATION

PROSPERO 2015: CRD42015026144 .

Epidemiology and cost of herpes zoster and postherpetic neuralgia in Germany

After acquiring a varicella virus infection, the virus can reactivate and cause herpes zoster (HZ)--a painful skin rash. A complication of HZ is long-term persistence of pain after the rash has resolved (so-called postherpetic neuralgia, PHN). We aimed to describe the epidemiology of HZ/PHN and to estimate HZ/PHN-related costs in the German statutory health insurance (SHI) system (~85% of the total population). Treatment data of one large SHI was utilized, containing data on approximately 240,000 insured and their utilisation of services in 2004-2009. Identification of HZ- and PHN-cases was performed based on 'International Statistical Classification of Diseases' and specific medications using a control-group design. Incidences per 1,000 person-years (PY) and cost-of-illness for 1 year following HZ-onset considering the payer and societal perspective were calculated. All amounts were inflated to 2010 Euros. Population-figures were standardised and extrapolated to the total SHI-population in Germany in 2010. A mean annual incidence of 5.79 HZ-cases per 1,000 PY was observed, translating into an estimated 403,625 HZ-cases per year in the total SHI-population. Approximately 5% of HZ-cases developed PHN. One HZ-case caused on average euro 210 and euro 376 of costs from the payer and societal perspective, respectively. The development of PHN generated additional costs of euro 1,123 (euro 1,645 societal perspective). Total annual HZ/PHN-related costs were estimated at euro 182 million (euro 105 million) to society (payer). HZ and PHN place a considerable burden on the German SHI-system. Since HZ-vaccines will soon be available, a health-economic evaluation of these vaccines should be conducted.

Health economic evaluation of vaccination strategies for the prevention of herpes zoster and postherpetic neuralgia in Germany

BACKGROUND

Herpes zoster (HZ) is a self-limiting painful skin rash affecting mostly individuals from 50 years of age. The main complication is postherpetic neuralgia (PHN), a long-lasting pain after rash has resolved. A HZ-vaccine has recently been licensed in Europe for individuals older than 50 years. To support an informed decision-making for a potential vaccination recommendation, we conducted a health economic evaluation to identify the most cost-effective vaccination strategy.

METHODS

We developed a static Markov-cohort model, which compared a vaccine-scenario with no vaccination. The cohort entering the model was 50 years of age, vaccinated at age 60, and stayed over life-time in the model. Transition probabilities were based on HZ/PHN-epidemiology and demographic data from Germany, as well as vaccine efficacy (VE) data from clinical trials. Costs for vaccination and HZ/PHN-treatment (in Euros; 2010), as well as outcomes were discounted equally with 3% p.a. We accounted results from both, payer and societal perspective. We calculated benefit-cost-ratio (BCR), number-needed-to-vaccinate (NNV), and incremental cost-effectiveness ratios (ICERs) for costs per HZ-case avoided, per PHN-case avoided, and per quality-adjusted life-year (QALY) gained. Different target age-groups were compared to identify the most cost-effective vaccination strategy. Base-case-analysis as well as structural, descriptive-, and probabilistic-sensitivity-analyses (DSA, PSA) were performed.

RESULTS

When vaccinating 20% of a cohort of 1 million 50 year old individuals at the age of 60 years, approximately 20,000 HZ-cases will be avoided over life-time. The NNV to avoid one HZ (PHN)-case was 10 (144). However, with a BCR of 0.34 this vaccination-strategy did not save costs. The base-case-analysis yielded an ICER of 1,419 (20,809) Euros per avoided HZ (PHN)-case and 28,146 Euros per QALY gained. Vaccination at the age of 60 was identified in most (sensitivity) analyses to be the most cost-effective vaccination strategy. In DSA, vaccine price and VE were shown to be the most critical input-data.

CONCLUSIONS

According to our evaluation, HZ-vaccination is expected to avoid HZ/PHN-cases and gain QALYs to higher costs. However, the vaccine price had the highest impact on the ICERs. Among different scenarios, targeting individuals aged 60 years seems to represent the most cost-effective vaccination-strategy.