Varicella zoster virus vaccines: potential complications and possible improvements

Varicella zoster virus (VZV) is the causative agent of varicella (chicken pox) and herpes zoster (shingles). After primary infection, the virus remains latent in sensory ganglia, and reactivates upon weakening of the cellular immune system due to various conditions, erupting from sensory neurons and infecting the corresponding skin tissue. The current varicella vaccine (v-Oka) is highly attenuated in the skin, yet retains its neurovirulence and may reactivate and damage sensory neurons. The reactivation is sometimes associated with postherpetic neuralgia (PHN), a severe pain along the affected sensory nerves that can linger for years, even after the herpetic rash resolves. In addition to the older population that develops a secondary infection resulting in herpes zoster, childhood breakthrough herpes zoster affects a small population of vaccinated children. There is a great need for a neuro-attenuated vaccine that would prevent not only the varicella manifestation, but, more importantly, any establishment of latency, and therefore herpes zoster. The development of a genetically-defined live-attenuated VZV vaccine that prevents neuronal and latent infection, in addition to primary varicella, is imperative for eventual eradication of VZV, and, if fully understood, has vast implications for many related herpesviruses and other viruses with similar pathogenic mechanisms.

Altered phenotype and functionality of varicella zoster virus-specific cellular immunity in individuals with active infection

BACKGROUND

Varicella zoster virus (VZV) establishes lifelong persistence and may reactivate in individuals with impaired immune function. To investigate immunologic correlates of protection and VZV reactivation, we characterized specific immunity in 207 nonsymptomatic immunocompetent and 132 immunocompromised individuals in comparison with patients with acute herpes zoster.

METHODS

VZV-specific CD4 T cells were quantified flow cytometrically after stimulation and characterized for expression of interferon-γ, interleukin 2, and tumor necrosis factor α and surface markers for differentiation (CD127) and anergy (cytotoxic T lymphocyte antigen 4 [CTLA-4] and programmed death [PD]-1). Immunoglobulin G and A levels were quantified using an enzyme-linked immunosorbent assay.

RESULTS

In healthy individuals, VZV-specific antibody and T-cell levels were age dependent, with the highest median VZV-specific CD4 T-cell frequencies of 0.108% (interquartile range, 0.121%) during adolescence. VZV-specific T-cell profiles were multifunctional with predominant expression of all 3 cytokines, CD127 positivity, and low expression of CTLA-4 and PD-1. Nonsymptomatic immunocompromised patients had similar VZV-specific immunologic properties except for lower T-cell frequencies (P<.001) and restricted cytokine expression. In contrast, significantly elevated antibody- and VZV-specific CD4 T-cell levels were found in patients with zoster. Their specific T cells showed a shift in cytokine expression toward interferon γ single positivity, an increase in CTLA-4 and PD-1, and a decrease in CD127 expression (all P<.001). This phenotype normalized after resolution of symptoms.

CONCLUSIONS

VZV-specific CD4-T cells in patients with zoster bear typical features of anergy. This phenotype is reversible and may serve as adjunct tool for monitoring VZV reactivations in high-risk patients.

Herpes zoster ophthalmicus following onabotulinumtoxinA administration for chronic migraine: a case report and literature review

BACKGROUND

There is a growing body of literature documenting local herpes zoster outbreak following procedures. The mechanism underlying these outbreaks remains elusive. We present a case of zoster following onabotulinumtoxinA (BTX) for migraine and a literature review.

METHODS

Chart and literature review.

CASE

A 72-year-old woman with chronic migraine received BTX injections for 3 years without incident. She had a history of thoracic zoster with subsequent post-herpetic neuralgia. In August 2013, 48 hours after receiving BTX injections, she developed a painful rash in the right V1 distribution consistent with herpes zoster ophthalmicus. One week later the rash had resolved without treatment.

LITERATURE REVIEW

We identified 65 (including 2 from Juel-Jenson) cases of zoster reactivation following minor procedures. These cases tend to be in young patients without specific risk factors. Outbreaks characteristically occur at the level of exposure to local trauma.

DISCUSSION

Our review suggests that local trauma, regardless of the nature of stimuli, may be sufficient for zoster reactivation. We hypothesize that the stressors in these reported cases exert a local epigenetic influence on viral transcription, allowing for viral reactivation.

CONCLUSION

Zoster is a potential complication of BTX administration for chronic migraine in adults. Physician awareness can reduce the significant morbidity associated with this disease.

Herpes zoster and postherpetic neuralgia: an examination of psychological antecedents

Herpes zoster and an associated complication, postherpetic neuralgia, are both attributable to the varicella zoster virus. This virus, which lies dormant within the affected sensory ganglia after an initial infection, appears to be triggered in part by a decrease in immunity. According to available research, stress, stressful life events, and depressive symptoms are identified antecedents to outbreaks of herpes zoster. Likewise, the development of postherpetic neuralgia has been associated with the psychological antecedents of somatization, nonspecific personality psychopathology, hypochondriasis, and somatic symptoms. Also studied, the role of mood and anxiety symptoms as antecedents for postherpetic neuralgia remains controversial. In conjunction with other factors (e.g., age, nutritional status, comorbid medical diseases), stress and psychological symptoms may contribute to a lowering of immunity and thereby function as antecedents as well as consequents of both herpes zoster and postherpetic neuralgia. Few studies have examined explicit psychiatric diagnoses and their association with varicella zoster virus reactivation.

Cost-effectiveness of vaccination against herpes zoster and postherpetic neuralgia: a critical review

OBJECTIVE

The objective of this study was to systematically review cost-effectiveness studies of vaccination against herpes zoster (HZ) and postherpetic neuralgia (PHN).

METHODS

We searched MEDLINE and EMBASE databases for eligible studies published prior to November 2013. We extracted information regarding model structure, model input parameters, and study results. We compared the results across studies by projecting the health and economic impacts of vaccinating one million adults over their lifetimes.

RESULTS

We identified 15 cost-effectiveness studies performed in North America and Europe. Results ranged from approximately US$10,000 to more than US$100,000 per quality-adjusted life years (QALY) gained. Most studies in Europe concluded that zoster vaccination is likely to be cost-effective. Differences in results among studies are largely due to differing assumptions regarding duration of vaccine protection and a loss in quality of life associated with HZ and to a larger extent, PHN. Moreover, vaccine efficacy against PHN, age at vaccination, and vaccine cost strongly influenced the results in sensitivity analyses.

CONCLUSION

Most studies included in this review shows that vaccination against HZ is likely to be cost-effective. Future research addressing key model parameters and cost-effectiveness studies in other parts of the world are needed.

Cost-effectiveness of vaccination against herpes zoster

Herpes zoster (HZ) is a common disease among elderly, which may develop into a severe pain syndrome labeled postherpetic neuralgia (PHN). A live-attenuated varicella zoster virus vaccine has been shown to be effective in reducing the incidence and burden of illness of HZ and PHN, providing the opportunity to prevent significant health-related and financial consequences of HZ. In this review, we summarize the available literature on cost-effectiveness of HZ vaccination and discuss critical parameters for cost-effectiveness results. A search in PubMed and EMBASE was performed to identify full cost-effectiveness studies published before April 2013. Fourteen cost-effectiveness studies were included, all performed in western countries. All studies evaluated cost-effectiveness among elderly above 50 years and used costs per quality-adjusted life year (QALY) gained as primary outcome. The vast majority of studies showed vaccination of 60- to 75-year-old individuals to be cost-effective, when duration of vaccine efficacy was longer than 10 years. Duration of vaccine efficacy, vaccine price, HZ incidence, HZ incidence and discount rates were influential to the incremental cost-effectiveness ratio (ICER). HZ vaccination may be a worthwhile intervention from a cost-effectiveness point of view. More extensive reporting on methodology and more detailed results of sensitivity analyses would be desirable to address uncertainty and to guarantee optimal comparability between studies, for example regarding model structure, discounting, vaccine characteristics and loss of quality of life due to HZ and PHN.

Vaccine acceptance: the UK perspective

The United Kingdom has had a long history with vaccine acceptability dating back to Edward Jenner's theory of small pox vaccination. More recently, the discredited, Wakefield study published in 1998 continues to cause MMR skepticism. In pregnant women pertussis vaccination has been considerably more successful than influenza vaccination. Influenza vaccine uptake in healthcare workers remains poor. The media, politicians, and health reforms have contributed to the mixed coverage for these vaccines. In this article we examine vaccine acceptability from a UK perspective, and consider the future impact this is likely to have on the introduction of rotavirus and shingles vaccine in the UK in 2013.

Active Shingles Infection as Detected on (18)F-FDG PET/CT

We present the case of a 56-year-old male with a history of recurrent follicular lymphoma undergoing chemotherapy with multiple (18)F-FDG PET-CT studies at an outside facility. He developed a painful erythematous, pruritic rash in the left back requiring a visit to the emergency room. He was diagnosed and treated for Varicella zoster infection. He then presented to our imaging center 2 months later for a follow up (18)F-FDG PET/CT study. Imaging demonstrated a cutaneous band of increased metabolic activity in the upper back following a dermatomal distribution. This was confirmed to be in the same area as the treated Varicella zoster eruption. A subsequent follow up (18)F-FDG PET-CT scan 4 months later to confirm tumor resolution demonstrated the abnormal band of uptake in the back had resolved. This case illustrates the significance of being aware of this entity and to distinguish it from metastasis, especially in patients with a known history of malignancy.

Review of the United States universal varicella vaccination program: Herpes zoster incidence rates, cost-effectiveness, and vaccine efficacy based primarily on the Antelope Valley Varicella Active Surveillance Project data

In a cooperative agreement starting January 1995, prior to the FDA's licensure of the varicella vaccine on March 17, the Centers for Disease Control and Prevention (CDC) funded the Los Angeles Department of Health Services' Antelope Valley Varicella Active Surveillance Project (AV-VASP). Since only varicella case reports were gathered, baseline incidence data for herpes zoster (HZ) or shingles was lacking. Varicella case reports decreased 72%, from 2834 in 1995 to 836 in 2000 at which time approximately 50% of children under 10 years of age had been vaccinated. Starting in 2000, HZ surveillance was added to the project. By 2002, notable increases in HZ incidence rates were reported among both children and adults with a prior history of natural varicella. However, CDC authorities still claimed that no increase in HZ had occurred in any US surveillance site. The basic assumptions inherent to the varicella cost-benefit analysis ignored the significance of exogenous boosting caused by those shedding wild-type VZV. Also ignored was the morbidity associated with even rare serious events following varicella vaccination as well as the morbidity from increasing cases of HZ among adults. Vaccine efficacy declined below 80% in 2001. By 2006, because 20% of vaccinees were experiencing breakthrough varicella and vaccine-induced protection was waning, the CDC recommended a booster dose for children and, in 2007, a shingles vaccination was approved for adults aged 60 years and older. In the prelicensure era, 95% of adults experienced natural chickenpox (usually as children)-these cases were usually benign and resulted in long-term immunity. Varicella vaccination is less effective than the natural immunity that existed in prevaccine communities. Universal varicella vaccination has not proven to be cost-effective as increased HZ morbidity has disproportionately offset cost savings associated with reductions in varicella disease. Universal varicella vaccination has failed to provide long-term protection from VZV disease.

Association between the initiation of anti-tumor necrosis factor therapy and the risk of herpes zoster

IMPORTANCE

Herpes zoster reactivation disproportionately affects patients with rheumatoid arthritis (RA). It is unclear whether anti-tumor necrosis factor (anti-TNF) therapy elevates herpes zoster risk.

OBJECTIVES

To ascertain whether initiation of anti-TNF therapy compared with nonbiologic comparators is associated with increased herpes zoster risk.

DESIGN, SETTING, AND PATIENTS

We identified new users of anti-TNF therapy among cohorts of patients with RA, inflammatory bowel disease, and psoriasis, psoriatic arthritis, or ankylosing spondylitis from 1998 through 2007 within a large US multi-institutional collaboration combining data from Kaiser Permanente Northern California, Pharmaceutical Assistance Contract for the Elderly, Tennessee Medicaid, and national Medicaid/Medicare programs. We compared herpes zoster incidence between new anti-TNF users (n=33,324) and patients initiating nonbiologic disease-modifying antirheumatic drugs (DMARDs) (n=25,742) within each inflammatory disease cohort (last participant follow-up December 31, 2007). Within these cohorts, we used Cox regression models to compare propensity score-adjusted herpes zoster incidence between new anti-TNF and nonbiologic DMARD users while controlling for baseline corticosteroid use.

MAIN OUTCOME MEASURES

Incidence of herpes zoster cases occurring after initiation of new anti-TNF or nonbiologic DMARD therapy.

RESULTS

Among 33,324 new users of anti-TNF therapy, we identified 310 herpes zoster cases. Crude incidence rates among anti-TNF users were 12.1 per 1000 patient-years (95% CI, 10.7-13.6) for RA, 11.3 per 1000 patient-years (95% CI, 7.7-16.7) for inflammatory bowel disease, and 4.4 per 1000 patient-years (95% CI, 2.8-7.0) for psoriasis, psoriatic arthritis, or ankylosing spondylitis. Baseline use of corticosteroids of 10 mg/d or greater among all disease indications was associated with elevated risk (adjusted hazard ratio [HR], 2.13 [95% CI, 1.64-2.75]) compared with no baseline use. For patients with RA, adjusted incidence rates were similar between anti-TNF and nonbiologic DMARD initiators (adjusted HR, 1.00 [95% CI, 0.77-1.29]) and comparable between all 3 anti-TNF therapies studied. Across all disease indications, the adjusted HR was 1.09 (95% CI, 0.88-1.36).

CONCLUSION AND RELEVANCE

Among patients with RA and other inflammatory diseases, those who initiated anti-TNF therapies were not at higher risk of herpes zoster compared with patients who initiated nonbiologic treatment regimens.

Childhood varicella-zoster virus vaccination in Belgium: cost-effective only in the long run or without exogenous boosting?

AIM

To assess the effectiveness and cost-effectiveness of a universal childhood varicella-zoster vaccination programme in Belgium (1) using the most recent Belgian data on varicella-zoster burden, (2) exploring different options for the timing of the second dose, (3) obtaining results with and without exogenous natural boosting, and (4) investigating the possible additional benefit of zoster booster vaccination for adults at age 50 or 60 y.

METHODS

An extensively studied and improved dynamic model is used to estimate primary and breakthrough chickenpox and zoster cases over time. For a range of vaccination options, we compared the direct costs (health care payer perspective) and health outcomes (including Quality-Adjusted Life-Years (QALYs) lost) associated with chickenpox and herpes zoster. Estimates of social contact patterns, health care use, costs and QALY losses are almost exclusively based on Belgian databases and surveys.

RESULTS AND CONCLUSIONS

If exogenous natural boosting exists, a net loss in QALYs is expected for several decades after implementing a universal chickenpox vaccination programme, due to an increase in zoster mainly in persons aged 50-80 y. This result holds also for scenarios that minimise or counteract the expected increase in zoster incidence (e.g. additional booster vaccinations in adults). However, if the boosting hypothesis is not true or if costs and QALYs are cumulated over at least 33 to more than 100 y after vaccination (depending on the assumptions made), different options for universal 2-dose vaccination against chickenpox in Belgium would be cost-effective at a vaccine price of €43/dose or lower.

Efficacy of live zoster vaccine in preventing zoster and postherpetic neuralgia

Declining cell-mediated immunity to varicella zoster virus (VZV) in elderly individuals results in virus reactivation manifest by zoster (shingles) and postherpetic neuralgia (PHN). To prevent virus reactivation, a new VZV vaccine (Zostavax; Merck) that boosts cell-mediated immunity to VZV was developed. The 3-year Shingles Prevention Study showed that Zostavax significantly reduced burden of disease because of zoster and PHN. Despite its cost-effectiveness for adults aged 65-75 years, as determined in the United States, Canada and UK, <2% of immunocompetent adults over age 60 years in the United States were immunized in 2007. This was because of a combination of lack of patient awareness of the vaccine, physicians' uncertainty about the duration of protection and different cost-sharing plans for immunization. Nevertheless, zoster vaccine is safe, effective and highly recommended for immunization of immunocompetent individuals over age 60 years with no history of recent zoster.

Prevention of shingles: safety and efficacy of live zoster vaccine

Primary infection with varicella zoster virus (VZV) causes chickenpox (varicella) after which virus becomes latent in cranial nerve, dorsal root and autonomic ganglia along the entire neuraxis. Virus may later reactivate, causing shingles (zoster), characterized by pain and rash restricted to 1-3 dermatomes. More than 40% of zoster patients over age 60 develop postherpetic neuralgia (PHN), pain that persists for months to years. The socioeconomic impact of primary varicella infection has been lessened by introduction of VZV vaccine for children. However, the effect of childhood vaccination on the incidence of zoster is unknown. Virus reactivation correlates with waning cell-mediated immunity (CMI) to VZV with normal aging. Adults exposed to children with varicella may have a boost in CMI to VZV. For at least several more decades, the incidence of zoster may increase as the elderly population grows. The anticipated increase in zoster burden of illness in future decades was a major impetus for the Shingles Prevention Study, a prospective, double-blind, placebo-controlled trial of attenuated VZV vaccine to prevent zoster in older adults. This review discusses clinical and virological aspects of zoster and its complications, current treatment options, and VZV vaccine development along with its future role in disease prevention.

Natural selection for rash-forming genotypes of the varicella-zoster vaccine virus detected within immunized human hosts

The Oka vaccine strain is a live attenuated virus that is routinely administered to children in the United States and Europe to prevent chickenpox. It is effective and safe but occasionally produces a rash. The vaccine virus has accumulated mutations during its attenuation, but the rashes are not explained by their reversion, unlike complications reported for other viral vaccines. Indeed, most of the novel mutations distinguishing the Oka vaccine from the more virulent parental virus have not actually become fixed. Because the parental alleles are still present, the vaccine is polymorphic at >30 loci and therefore contains a mixture of related viruses. The inoculation of >40 million patients has consequently created a highly replicated evolutionary experiment that we have used to assess the competitive ability of these different viral genotypes in a human host. Using virus recovered from rash vesicles, we show that two vaccine mutations, causing amino acid substitutions in the major transactivating protein IE62, are outcompeted by the ancestral alleles. Standard interpretations of varicella disease severity concentrate on the undeniably important effects of host genotype and immune status, yet our results allow us to demonstrate that the viral genotype is associated with virulence and to identify the key sites. We propose that these loci have pleiotropic effects on the immunogenic properties of the virus, rash formation, and its epidemiological spread, which mould the evolution of its virulence. These findings are of practical importance for reducing the incidence of vaccine-associated rash and promoting public acceptance of the vaccine.

Synthesis of Organotin Polyamine Ethers Containing Acyclovir and their Preliminary Anticancer and Antiviral Activity

Organotin polyamine ethers containing acyclovir in their backbone were synthesized in moderate to high yield employing the aqueous interfacial polycondensation system. The products are high molecular weight polymers. Infrared spectroscopy of the products shows new bands characteristic of the formation of Sn-N and Sn-O bonds consistent with the proposed structure. MALDI-TOF MS below 2000 Da shows the presence of organotin and acyclovir units containing these two moieties. The products show moderate inhibition of a number of cancer cell lines and exhibit the ability to inhibit a number of viruses, particularly the herpes simplex virus-1 and varicella zoster virus that are responsible for herpes, chicken pox and shingles.

Case report: occupationally related recurrent varicella (chickenpox) in a hospital nurse

Commonly accepted outcomes of varicella-zoster virus (VZV) infections include chickenpox (primary) and shingles (recurrence or latency), as well lifetime immunity against chickenpox. We report the case of a registered nurse who worked in a neurologic surgery ward in a general hospital in Taipei, Taiwan. While working there for approximately 1 year, she developed recurrent chickenpox after caring for a paraparesis patient, who had herpes zoster during hospitalization in August 2002. The varicella incubation period was 10 days, which matched the range (10-21 days). Recently negative specific serum IgM and positive specific serum IgG indicated a past VZV infection. The nurse did not get herpes zoster from the second episode of varicella on 9 August 2002 to 4 April 2005 and is now convalescing. We conclude that occupational VZV hazards exist in the health care environment and suggest testing for VZV antibody and a VZV vaccination program for susceptible health care workers. Key words: chickenpox, indirect fluroscent antibody, occupational exposure, polymerase chain reaction, shingles, Taiwan, varicella-zoster virus.

The incidence of herpes zoster in a United States administrative database

BACKGROUND

Few recent studies have reported data on the incidence of herpes zoster (HZ) in U.S. general clinical practice.

OBJECTIVE

To estimate the age- and sex-specific incidence of HZ among U.S. health plan enrollees.

DESIGN

Data for the years 2000 to 2001 were obtained from the Medstat MarketScan database, containing health insurance enrollment and claims data from over 4 million U.S. individuals. Incident HZ cases were identified through HZ diagnosis codes on health care claims. The burden of HZ among high-risk individuals with recent care for cancer, HIV, or transplantation was examined in sub-analyses. Overall incidence rates were age- and sex-adjusted to the 2000 U.S. population.

PARTICIPANTS

MarketScan U.S. health plan enrollees of all ages.

MEASUREMENTS AND MAIN RESULTS

We identified 9,152 incident cases of HZ (3.2 per 1,000 person-years) (95% confidence interval [CI], 3.1 to 3.2 per 1,000). Annual HZ rates per 1,000 person-years were higher among females (3.8) than males (2.6) (P<.0001). HZ rates rose sharply with age, and were highest among individuals over age 80 (10.9 per 1,000 person-years) (95% CI, 10.2 to 11.6). The incidence of HZ per 1,000 person-years among patients with evidence of recent care for transplantation, HIV infection, or cancer (10.3) was greater than for individuals without recent care for these conditions (3.0) (P<.0001).

CONCLUSIONS

The overall incidence of HZ reported in the present study was found to be similar to rates observed in U.S. analyses conducted 10 to 20 years earlier, after age- and sex-standardizing estimates from all studies to the 2000 U.S. population. The higher rate of HZ in females compared with males contrasts with prior U.S. studies.

Shingles Immunity and Health Functioning in the Elderly: Tai Chi Chih as a Behavioral Treatment

Both the incidence and severity of herpes zoster (HZ) or shingles increase markedly with increasing age in association with a decline in varicella zoster virus (VZV)-specific immunity. Considerable evidence shows that behavioral stressors, prevalent in older adults, correlate with impairments of cellular immunity. Moreover, the presence of depressive symptoms in older adults is associated with declines in VZV-responder cell frequency (VZV-RCF), an immunological marker of shingles risk. In this review, we discuss recent findings that administration of a relaxation response-based intervention, tai chi chih (TCC), results in improvements in health functioning and immunity to VZV in older adults as compared with a control group. TCC is a slow moving meditation consisting of 20 separate standardized movements which can be readily used in elderly and medically compromised individuals. TCC offers standardized training and practice schedules, lending an important advantage over prior relaxation response-based therapies. Focus on older adults at increased risk for HZ and assay of VZV-specific immunity have implications for understanding the impact of behavioral factors and a behavioral intervention on a clinically relevant end-point and on the response of the immune system to infectious pathogens.