Herpes zoster and the search for an effective vaccine

Skin manifestations after immunisation with an adjuvanted recombinant zoster vaccine, Germany, 2020

BackgroundShortly after the launch of a novel adjuvanted recombinant zoster vaccine (RZV), Shingrix, cases of suspected herpes zoster (HZ) or zoster-like skin reactions following immunisation were reported.AimWe aimed to investigate if these skin manifestations after administration of RZV could be HZ.MethodsBetween April and October 2020, general practitioners (GP) reporting a suspected case of HZ or zoster-like skin manifestation after RZV vaccination to the Paul-Ehrlich-Institut, the German national competent authority, were invited to participate in the study. The GP took a sample of the skin manifestation, photographed it and collected patient information on RZV vaccination and the suspected adverse event. We analysed all samples by PCR for varicella-zoster virus (VZV) and herpes-simplex virus (HSV) and genotyped VZV-positive samples. In addition, cases were independently assessed by two dermatologists.ResultsEighty eligible cases were enrolled and 72 could be included in the analysis. Of the 72 cases, 45 were female, 33 were 60-69 years old, 32 had skin symptoms in the thoracic and 27 in the cervical dermatomes. Twenty-seven samples tested PCR positive for VZV (all genotyped as wild-type, WT), three for HSV-1 and five for HSV-2.ConclusionIt may be difficult to distinguish HZ, without a PCR result, from other zoster-like manifestations. In this study, VZV-PCR positive dermatomal eruptions occurring in the first weeks after immunisation with RZV were due to WT VZV, which is not unexpected as HZ is a common disease against which the vaccine is unlikely to provide full protection at this time.

Safety of JAK inhibitor use in patients with rheumatoid arthritis who developed herpes zoster after receiving JAK inhibitors

INTRODUCTION

To determine the safety of Janus kinase inhibitor (JAKi) use following herpes zoster (HZ) reactivation in patients with rheumatoid arthritis (RA).

METHODS

Medical records of all patients who received JAKi at a tertiary referral center between August 2015 and June 2021 were retrospectively reviewed. Data from patients who developed HZ reactivation were collected, and the HZ-related safety of those who continued JAKis after reactivation was evaluated.

RESULTS

Of the 416 patients who received JAKis, 33 (7.9%) developed HZ reactivation during treatment (tofacitinib, n = 22; baricitinib, n = 11). The mean age of the patients was 60.2 ± 11.8 years. Fourteen patients (42.4%) received glucocorticoids with a median dose of 3.75 mg of prednisone (IQR, 2.5-5.0). The median duration of JAKi administration before HZ reactivation was 11 months (IQR, 4-29). JAKi was continued in 24 (72.7%) patients during the HZ episode, while it was temporarily discontinued and then resumed after the HZ episode in 5 (15.2%) patients. Three (9.1%) patients had acute complications, such as encephalitis with HZ ophthalmicus. Four (12.1%) patients, including the 3 with complications, permanently discontinued JAKis. Of the 29 patients who were observed for a median of 12 months (IQR, 6-21) after the initial HZ reactivation episode, reactivation recurred in one (3.4%); this patient maintained JAKi treatment for a further 18 months without additional HZ recurrence.

CONCLUSION

JAKis were commonly continued or re-administered in patients with HZ reactivation, and the majority of these patients did not experience significant complications or recurrence of HZ reactivation. Thus, the use of JAKi after HZ reactivation episode seems to be tolerated.

Aging and Options to Halt Declining Immunity to Virus Infections

Immunosenescence is a process associated with aging that leads to dysregulation of cells of innate and adaptive immunity, which may become dysfunctional. Consequently, older adults show increased severity of viral and bacterial infections and impaired responses to vaccinations. A better understanding of the process of immunosenescence will aid the development of novel strategies to boost the immune system in older adults. In this review, we focus on major alterations of the immune system triggered by aging, and address the effect of chronic viral infections, effectiveness of vaccination of older adults and strategies to improve immune function in this vulnerable age group.

A fixed nitrous oxide/oxygen mixture as an analgesic for patients with postherpetic neuralgia: study protocol for a randomized controlled trial

BACKGROUND

The pain management of postherpetic neuralgia (PHN) remains a major challenge, with no immediate relief. Nitrous oxide/oxygen mixture has the advantages of quick analgesic effect and well-tolerated. The purpose of this study is to investigate the analgesic effect and safety of nitrous oxide/oxygen mixture in patients with PHN.

METHODS/DESIGN

This study is a single-center, two-group (1:1), randomized, placebo-controlled, double-blind clinical trial. A total of 42 patients with postherpetic neuralgia will be recruited and randomly divided into the intervention group and the control group. The control group will receive routine treatment plus oxygen, and the intervention group will receive routine treatment plus nitrous oxide/oxygen mixture. Data collectors, patients, and clinicians are all blind to the therapy. The outcomes of each group will be monitored at baseline (T0), 5 min (T1), and 15 min (T2) after the start of the therapy and at 5 min after the end of the therapy (T3). The primary outcome measure will be the pain intensity. Secondary outcomes included physiological parameters, adverse effects, patients' acceptance of analgesia, and satisfaction from patients.

DISCUSSION

Previous studies have shown that nitrous oxide/oxygen mixture can effectively relieve cancer patients with breakthrough pain. This study will explore the analgesic effect of oxide/oxygen mixture on PHN. If beneficial to patients with PHN, it will contribute to the pain management of PHN.

TRIAL REGISTRATION

Chinese Clinical Trial Register ChiCTR1900023730 . Registered on 9 June 2019.

Progress and Pitfalls in the Quest for Effective SARS-CoV-2 (COVID-19) Vaccines

There are currently around 200 SARS-CoV-2 candidate vaccines in preclinical and clinical trials throughout the world. The various candidates employ a range of vaccine strategies including some novel approaches. Currently, the goal is to prove that they are safe and immunogenic in humans (phase 1/2 studies) with several now advancing into phase 2 and 3 trials to demonstrate efficacy and gather comprehensive data on safety. It is highly likely that many vaccines will be shown to stimulate antibody and T cell responses in healthy individuals and have an acceptable safety profile, but the key will be to confirm that they protect against COVID-19. There is much hope that SARS-CoV-2 vaccines will be rolled out to the entire world to contain the pandemic and avert its most damaging impacts. However, in all likelihood this will initially require a targeted approach toward key vulnerable groups. Collaborative efforts are underway to ensure manufacturing can occur at the unprecedented scale and speed required to immunize billions of people. Ensuring deployment also occurs equitably across the globe will be critical. Careful evaluation and ongoing surveillance for safety will be required to address theoretical concerns regarding immune enhancement seen in previous contexts. Herein, we review the current knowledge about the immune response to this novel virus as it pertains to the design of effective and safe SARS-CoV-2 vaccines and the range of novel and established approaches to vaccine development being taken. We provide details of some of the frontrunner vaccines and discuss potential issues including adverse effects, scale-up and delivery.

Prophylactic vaccination with a live-attenuated herpes zoster vaccine in lung transplant candidates

BACKGROUND

Herpes zoster (HZ) is caused by the reactivation of varicella-zoster virus (VZV). Patients with lung transplants are at high risk for HZ owing to their immunocompromised status and the need for lifelong immunosuppression. In this study, patients on the waiting list for lung transplantation were vaccinated by a live-attenuated HZ vaccine (Zostavax, Merck Sharp & Dohme), and the safety and immunogenicity of this vaccine were studied.

METHODS

In total, 105 patients with end-stage pulmonary disease (ESPD) were enrolled (68 participants received 1 dose of Zostavax and 37 participants were enrolled as unvaccinated controls). Among them, 43 patients underwent lung transplantation and were followed up for further analysis. VZV immunoglobulin G antibody titers and VZV-specific cell-mediated immunity (CMI) on multiple time points before and after vaccination and before and after transplantation were measured.

RESULTS

Immune response to Zostavax was higher in younger patients, highest within 3 months after vaccination, and not influenced by gender or type of ESPD. Age, cytomegalovirus serostatus, and immunity to VZV at baseline impacted the subsequent immune response to the vaccine. Short-term immunosuppressant treatment had strong effects on VZV CMI levels, which returned to a high level at 6 months after transplantation in vaccinated patients. Zostavax did not impact infection or rejection rate after transplantation.

CONCLUSIONS

Zostavax was safe and induced a robust humoral and cellular response for patients awaiting lung transplantation regardless of the type of ESPD. Patients younger than the recommended vaccination age of over 50 years showed a strong response and could also benefit from pre-transplant immunization.

Human NK Cells and Herpesviruses: Mechanisms of Recognition, Response and Adaptation

NK cells contribute to early defenses against viruses through their inborn abilities that include sensing of PAMPs and inflammatory signals such as cytokines or chemokines, recognition, and killing of infected cells through activating surface receptors engagement. Moreover, they support adaptive responses via Ab-dependent mechanisms, triggered by CD16, and DC editing. Their fundamental role in anti-viral responses has been unveiled in patients with NK cell deficiencies suffering from severe Herpesvirus infections. Notably, these infections, often occurring as primary infections early in life, can be efficiently cleared by NK, T, and B cells in healthy hosts. Herpesviruses however, generate a complicated balance with the host immune system through their latency cycle moving between immune control and viral reactivation. This lifelong challenge has contributed to the development of numerous evasion mechanisms by Herpesviruses, many of which devoted to elude NK cell surveillance from viral reactivations rather than primary infections. This delicate equilibrium can be altered in proportions of healthy individuals promoting virus reactivation and, more often, in immunocompromised subjects. However, the constant stimulus provided by virus-host interplay has also favored NK-cell adaptation to Herpesviruses. During anti-HCMV responses, NK cells can reshape their receptor repertoire and function, through epigenetic remodeling, and acquire adaptive traits such as longevity and clonal expansion abilities. The major mechanisms of recognition and effector responses employed by NK cells against Herpesviruses, related to their genomic organization will be addressed, including those allowing NK cells to generate memory-like responses. In addition, the mechanisms underlying virus reactivation or control will be discussed.

Pain management and stroke prevention in HHV-3-associated infection

The modern information on the epidemiology, pathogenesis, clinical manifestations, diagnosis and pain management in HHV-3-associated neuro-infection is presented. The criteria for the phased diagnostics and approaches to the rational therapy for shingles and postherpetic neuralgia are presented. The conditions aimed at the prevention of pain due to the damage to peripheral nervous system and stroke due to HHV-3-associated vasculopathy are discussed.

Varicella Virus-Host Interactions During Latency and Reactivation: Lessons From Simian Varicella Virus

Varicella zoster virus (VZV) is a neurotropic alphaherpesvirus and the causative agent of varicella (chickenpox) in humans. Following primary infection, VZV establishes latency in the sensory ganglia and can reactivate to cause herpes zoster, more commonly known as shingles, which causes significant morbidity, and on rare occasions mortality, in the elderly. Because VZV infection is highly restricted to humans, the development of a reliable animal model has been challenging, and our understanding of VZV pathogenesis remains incomplete. As an alternative, infection of rhesus macaques with the homologous simian varicella virus (SVV) recapitulates the hallmarks of VZV infection and thus constitutes a robust animal model to provide critical insights into VZV pathogenesis and the host antiviral response. In this model, SVV infection results in the development of varicella during primary infection, generation of an adaptive immune response, establishment of latency in the sensory ganglia, and viral reactivation upon immune suppression. In this review, we discuss our current knowledge about host and viral factors involved in the establishment of SVV latency and reactivation as well as the important role played by T cells in SVV pathogenesis and antiviral immunity.

Induction of plasmablasts by follicular helper T cell-CXCL13 axis upon occurrence of herpes zoster

Herpes zoster (HZ) is a recurrent varicella zoster virus (VZV) infection. Follicular helper T (Tfh) cells produce IL-21 and CXCL13, which contributes to the differentiation of plasmablasts. Plasmablasts are involved in the VZV-specific antibody production. We investigated the kinetics of circulating plasmablasts and circulating Tfh (cTfh) cells in 43 HZ patients. Plasma IL-21 and CXCL13 levels were also measured. We found an increase of circulating plasmablasts during the clinical course of HZ. The frequency of circulating plasmablasts positively correlated with VZV-specific IgG titers, frequency of activated cTfh cells, and plasma CXCL13 levels, but did not correlate with plasma IL-21 levels. In a representative case, the kinetics peaked in the order of cTfh cells, CXCL13, plasmablasts, and VZV IgG titer. These results suggest that cTfh-CXCL13 may have a crucial role in the differentiation of B cells into VZV-specific IgG-producing plasmablasts, resulting in boosting immunity against VZV reactivation.

Development of adjuvanted recombinant zoster vaccine and its implications for shingles prevention

INTRODUCTION

GSK has developed a two-dose adjuvanted recombinant zoster vaccine (Shingrix, RZV) to protect people aged ≥50 years (50+) against herpes zoster (HZ) and its complications. RZV showed >90% efficacy against HZ, sustained over 4 years of follow-up, in all studied age groups.

AREAS COVERED

This article reviews the scientific rationale underlying the design of RZV; the clinical evidence demonstrating immunogenicity, safety, and efficacy in persons 50+; and the public health implications and cost-effectiveness.

EXPERT COMMENTARY

A decline in varicella zoster virus (VZV) immunity is associated with increased risk of HZ in adults 50+ and immunocompromised individuals. RZV was designed to restore levels of anti-VZV cellular and humoral immunity to prevent VZV reactivation. RZV includes the recombinant gE glycoprotein antigen, and Adjuvant System AS01_B which promotes cellular and antibody responses. In two Phase III studies in subjects aged 50+ and 70+ years, RZV efficacy against HZ compared to placebo was >90% and ≥89% against post-herpetic neuralgia (PHN). RZV is expected to dramatically impact HZ morbidity including its complications, and associated health-care costs. In the US population aged 50+ years, vaccination with RZV can be cost-effective compared to no vaccination and cost-saving compared to the currently available live-attenuated HZ vaccine (Zostavax, Merck).

Varicella and herpes zoster vaccine development: lessons learned

INTRODUCTION

Before vaccination, varicella zoster virus (VZV), which is endemic worldwide, led to almost universal infection. This neurotropic virus persists lifelong by establishing latency in sensory ganglia, where its reactivation is controlled by VZV-specific T-cell immunity. Lifetime risk of VZV reactivation (zoster) is around 30%. Vaccine development was galvanised by the economic and societal burden of VZV, including debilitating zoster complications that largely affect older individuals. Areas covered: We describe the story of development, licensing and implementation of live attenuated vaccines against varicella and zoster. We consider the complex backdrop of VZV virology, pathogenesis and immune responses in the absence of suitable animal models and examine the changing epidemiology of VZV disease. We review the vaccines' efficacy, safety, effectiveness and coverage using evidence from trials, observational studies from large routine health datasets and clinical post-marketing surveillance studies and outline newer developments in subunit and inactivated vaccines. Expert commentary: Safe and effective, varicella and zoster vaccines have already made major inroads into reducing the burden of VZV disease globally. As these live vaccines have the potential to reactivate and cause clinical disease, developing alternatives that do not establish latency is an attractive prospect but will require better understanding of latency mechanisms.

Post-herpetic neuralgia - a review of current management and future directions

Post-herpetic neuralgia (PHN) is common and treatment is often suboptimal with less than half of patients achieving adequate 50% pain relief. As an area of unmet clinical need and as an archetype of neuropathic pain, it deserves the attention of clinicians and researchers. Areas covered: This review summarises the epidemiology, pathophysiology, risk factors and clinical features of varicella infection. It describes the current and possible future management strategies for preventing varicella infection and reactivation and for treating PHN. Expert opinion: A highly successful Varicella Zoster (VZV) vaccine has not been universally adopted due to fears that it may increase Herpes Zoster (HZ) incidence - and thus PHN - in older, unvaccinated generations. This is a controversial theory but advances in the efficacy of vaccines against HZ may allay these fears and encourage more widespread adoption of the VZV vaccine. Treatment of PHN, as for any neuropathic pain, must be multidisciplinary and multimodal. Advances in sensory phenotyping technology and genomics may allow more individualised treatment. Traditional research methodologies are ill-suited to assess the kind of complex interventions that are necessary to achieve better clinical outcomes in this challenging field.

Cutaneous infections in the mature patient

Dermatologists must be familiar with the peculiarities of the micro-organisms that may affect the elderly, in order to optimize the diagnosis and treatment of infections, which may affect their skin, especially because the world population is rapidly aging. It is estimated that there will be 434 million individuals over 80 years of age in 2050. Since the elderly population is rapidly increasing and their infections are usually more severe and different from those observed in younger adults, it leads to a statistical increase of the rates regarding hospitalization and mortality caused by infectious diseases among people over 85 years. Other health issues may be involved in the older population. These include nutritional alterations, as malnutrition or obesity, which can aggravate the infections. Also the usual signs and symptoms of infection are subtle or uncharacteristic in elderly patients, and frequently, they are unable to report their symptoms, which can delay the diagnosis. Among the many infections that may affect the elderly we reviewed the most frequent and those that are different in this age group, as herpes zoster, cytomegalovirus, herpes simplex, bacterial skin infections, erysipelas, celullitis, impetigo, folliculitis, furunculosis and carbunculosis, secondary infections, intertrigo (body folds), fungal infection, and scabies.