The herpes zoster subunit vaccine

HIV BG505 SOSIP.664 trimer with 3M-052-AF/alum induces human autologous tier-2 neutralizing antibodies

Stabilized trimers preserving the native-like HIV envelope structure may be key components of a preventive HIV vaccine regimen to induce broadly neutralizing antibodies (bnAbs). We evaluated trimeric BG505 SOSIP.664 gp140, formulated with a novel TLR7/8 signaling adjuvant, 3M-052-AF/Alum, for safety, adjuvant dose-finding and immunogenicity in a first-in-healthy adult (n=17), randomized, placebo-controlled trial (HVTN 137A). The vaccine regimen appeared safe. Robust, trimer-specific antibody, B-cell and CD4+ T-cell responses emerged post-vaccination. Five vaccinees developed serum autologous tier-2 nAbs (ID50 titer, 1:28-1:8647) after 2-3 doses targeting C3/V5 and/or V1/V2/V3 Env regions by electron microscopy and mutated pseudovirus-based neutralization analyses. Trimer-specific, B-cell-derived monoclonal antibody activities confirmed these results and showed weak heterologous neutralization in the strongest responder. Our findings demonstrate the clinical utility of the 3M-052-AF/alum adjuvant and support further improvements of trimer-based Env immunogens to focus responses on multiple broad nAb epitopes.

KEY TAKEAWAY/TAKE-HOME MESSAGES

HIV BG505 SOSIP.664 trimer with novel 3M-052-AF/alum adjuvant in humans appears safe and induces serum neutralizing antibodies to matched clade A, tier 2 virus, that map to diverse Env epitopes with relatively high titers. The novel adjuvant may be an important mediator of vaccine response.

Adjuvants in cutaneous vaccination: A comprehensive analysis

Skin is the body's largest organ and serves as a protective barrier from physical, thermal, and mechanical environmental challenges. Alongside, the skin hosts key immune system players, such as the professional antigen-presenting cells (APCs) like the Langerhans cells in the epidermis and circulating macrophages in the blood. Further, the literature supports that the APCs can be activated by antigen or vaccine delivery via multiple routes of administration through the skin. Once activated, the stimulated APCs drain to the associated lymph nodes and gain access to the lymphatic system. This further allows the APCs to engage with the adaptive immune system and activate cellular and humoral immune responses. Thus, vaccine delivery via skin offers advantages such as reliable antigen delivery, superior immunogenicity, and convenient delivery. Several preclinical and clinical studies have demonstrated the significance of vaccine delivery using various routes of administration via skin. However, such vaccines often employ adjuvant/(s), along with the antigen of interest. Adjuvants augment the immune response to a vaccine antigen and improve the therapeutic efficacy. Due to these reasons, adjuvants have been successfully used with infectious disease vaccines, cancer immunotherapy, and immune-mediated diseases. To capture these developments, this review will summarize preclinical and clinical study results of vaccine delivery via skin in the presence of adjuvants. A focused discussion regarding the FDA-approved adjuvants will address the experiences of using such adjuvant-containing vaccines. In addition, the challenges and regulatory concerns with these adjuvants will be discussed. Finally, the review will share the prospects of adjuvant-containing vaccines delivered via skin.

Insights into the Novel Therapeutics and Vaccines against Herpes Simplex Virus

Herpes simplex virus (HSV) is a great concern of the global health community due to its linked infection of inconspicuous nature and resultant serious medical consequences. Seropositive patients may develop ocular disease or genital herpes as characteristic infectious outcomes. Moreover, the infectious nature of HSV is so complex that the available therapeutic options have been modified in certain ways to cure it. However, no permanent and highly effective cure has been discovered. This review generates insights into the available prophylactic and therapeutic interventions against HSV. A methodological research approach is used for study design and data complication. Only the latest data from publications are acquired to shed light on updated therapeutic approaches. These studies indicate that the current antiviral therapeutics can suppress the symptoms and control viral transmission up to a certain level, but cannot eradicate the natural HSV infection and latency outcomes. Most trials that have entered the clinical phase are made part of this review to understand what is new within the field. Some vaccination approaches are also discussed. Moreover, some novel therapeutic options that are currently in research annals are given due consideration for future development. The data can enable the scientific community to direct their efforts to fill the gaps that remain unfilled in terms of therapies for HSV. The need is to integrate scientific efforts to produce a proper cure against HSV to control the virus spread, resistance, and mutation in future disease management.

T cell immunity in HSV-1- and VZV-infected neural ganglia

Herpesviruses hijack the MHC class I (MHC I) and class II (MHC II) antigen-presentation pathways to manipulate immune recognition by T cells. First, we illustrate herpes simplex virus-1 (HSV-1) and varicella-zoster virus (VZV) MHC immune evasion strategies. Next, we describe MHC-T cell interactions in HSV-1- and VZV- infected neural ganglia. Although studies on the topic are scarce, and use different models, most reports indicate that neuronal HSV-1 infection is mainly controlled by CD8+ T cells through noncytolytic mechanisms, whereas VZV seems to be largely controlled through CD4+ T cell-specific immune responses. Autologous human stem-cell-derived in vitro models could substantially aid in elucidating these neuroimmune interactions and are fit for studies on both herpesviruses.

Development of (Inhalable) Dry Powder Formulations of AS01B-Containing Vaccines Using Thin-Film Freeze-Drying

AS01_B is a liposomal formulation of two immunostimulants namely 3-O-desacyl-4́-monophosphoryl lipid A (MPL) and QS-21. The liposomal formulation of AS01_B reduces the endotoxicity of MPL and the lytic activity of QS-21. The AS01_B-adjuvanted Shingrix vaccine is marketed in a two-vial presentation, with the liquid AS01_B liposomes in one vial and the antigen as a dry powder in another vial. In the present study, we tested the feasibility of applying thin-film freeze-drying (TFFD) to engineer dry powders of the AS01_B liposomal adjuvant alone or vaccines containing AS01_B as an adjuvant. Initially, we showed that after the AS01_B liposomal adjuvant was subjected to TFFD using sucrose as a stabilizer at 4% w/v, the particle size distribution of AS01_B liposomes reconstituted from the dry powder was identical to the liquid adjuvant before drying. We then showed using ovalbumin (OVA) as a model antigen adjuvanted with AS01_B (AS01_B/OVA) that subjecting the AS01_B/OVA vaccine to TFFD and subsequent reconstitution did not negatively affect the AS01_B liposome particle size, nor the immunogenicity of the vaccine. Importantly, the thin-film freeze-dried AS01_B/OVA vaccine, unlike its liquid counterpart, was not sensitive to repeated freezing-and-thawing. The developed AS01_B/OVA dry powder also showed the desirable aerosol properties (i.e., fine particle fraction of 66.3 ± 4.9% and mass median aerodynamic diameter of 2.4 ± 0.1 µm) for potential pulmonary administration. Finally, the feasibility of using TFFD to prepare dry powders of AS01_B-adjuvanted vaccines was further confirmed using AS01_B-adjuvanted Fluzone Quadrivalent and Shingrix, which contains AS01_B. It is concluded that the TFFD technology can enable the formulation of AS01_B-adjuvanted vaccines as freezing-insensitive, inhalable dry powders in a single-vial presentation.

Long-term Risk of Herpes Zoster Infection in Patients With Ulcerative Colitis Receiving Tofacitinib

BACKGROUND

Tofacitinib is an oral, small molecule Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We report herpes zoster (HZ) incidence and risk factors in the tofacitinib UC clinical program (up to 7.8 years).

METHODS

Proportions and incidence rates (IRs; unique patients with events/100 patient-years) of HZ were evaluated in 4 cohorts: Induction (phase 2 and 3 induction study data), Maintenance (phase 3 maintenance study data), Overall (data from all phase 2, 3, and open-label, long-term extension studies), and Overall plus interim 6-month phase 3b and 4 data. Herpes zoster risk factors were assessed by Cox regression analysis.

RESULTS

In the Induction and Maintenance Cohorts, IRs for HZ (nonserious and serious) were numerically higher with tofacitinib 10 mg twice daily (BID) vs placebo and tofacitinib 10 vs 5 mg BID, respectively. With all tofacitinib doses (5 or 10 mg BID), IRs (95% confidence intervals) for HZ in the Overall and Overall plus phase 3b/4 Cohorts (total exposure, 2814.4 and 2999.7 patient-years, respectively) were 3.38 (2.73-4.15) and 3.30 (2.67-4.04), respectively. In the Overall plus phase 3b/4 Cohort, >90% of HZ were nonserious; >90% were mild/moderate; >90% resolved without discontinuing tofacitinib; 0.6% of patients had multiple HZ events. Herpes zoster IRs were stable when analyzed by 6-month intervals up to >30 months. Herpes zoster risk factors included older age, lower weight, geographic region, and prior tumor necrosis factor inhibitor (TNFi) failure.

CONCLUSIONS

Most HZ events were mild/moderate. Herpes zoster IRs remained stable over 7.8 years of exposure. Older age, lower weight, geographic region, and prior TNFi failure were associated with increased HZ risk.

CLINICALTRIALS.GOV

NCT00787202;NCT01465763;NCT01458951;NCT01458574;NCT01470612;NCT03281304.

Long-term efficacy data for the recombinant zoster vaccine: impact on public health and cost effectiveness in Germany

The aim of the study was to update previously published public health impact and cost-effectiveness analyses of the recombinant zoster vaccine (RZV), in the German population aged ≥50 years of age (YOA), with the latest vaccine efficacy (VE) estimates against herpes zoster (HZ). The updated estimates are derived from a long-term follow-up study. A previously published multi-cohort Markov model following age cohorts over their lifetime was used. Demographic, epidemiological, cost, and utility data were based on German specific sources. Vaccine coverage was assumed to be 40%, with a second dose compliance of 70%. The estimated VE at time 0 was 98.9% (95% C.I.: 94.0–100%) with an annual waning of 1.5% (95% CI: 0.0–3.4%) for the age group 50–69 YOA. Corresponding values were 95.4% (95% C.I.: 89.7–100%) and 2.3% (95% CI: 0.3–4.4%) for the age group ≥70 YOA. It was estimated that, over the remaining lifetime since vaccination, RZV would prevent approximately 884 thousand (K), 603 K, and 538 K HZ cases in three age cohorts 50–59, 60–69, and ≥70 YOA, respectively. The number needed to vaccinate to prevent one HZ and one postherpetic neuralgia case was 6 and 36 (50–59 YOA cohort), 6 and 34 (60–69 YOA cohort), 10 and 48 (≥70 YOA cohort). The incremental cost-effectiveness ratio of vaccination ranged from €26 K/quality-adjusted life year (QALY) in 60 YOA to €35 K/QALY in 70 YOA. Due to the higher, sustained, RZV VE, improved public health and cost-effectiveness results were observed compared to previous analyses.

What is the context?

Shingles is a viral infection caused by the reactivation of the chickenpox virus. It causes a painful rash that lasts for several weeks.

The incidence and severity of shingles increase with age. In Germany alone there are approximately 400,000 new cases annually.

Vaccination can help prevent shingles.

Previous studies, based on data collected up to four years post-vaccination, estimated the number of shingles cases prevented.

What is new?

Here, we use data from the same studies followed over a longer-term to update previous analyses in the German population.

We found, based on data up to 8 years following vaccination, that:

○ In adults 50-69 years: the vaccine initially prevents 98.9% of cases, with a reduction of 1.5% each year(for example, after one year, it would prevent 97.4% of cases).

○ In adults over 70 years of age: the vaccine initially prevents 95.4% of cases, with a reduction of 2.3% each year (for example, after one year, it would prevent 93.1% of cases).

○ Vaccination would reduce the number of shingles cases by 0.9 million in a cohort of adults aged 50-59 years, 0.6 million in adults 60-69 years, and 0.5 million in adults older than 70 years, over the remainder of their lifetime.

What is the impact?

The study provides more certainty regarding results as it is based on the most complete/up to date data.

The results showed the potential of Shingrix to prevent shingles while at the same time providing good value for money.

Psoriasis: To Vaccinate or Not to Vaccinate?

Psoriasis is a chronic, inflammatory, autoimmune disease characterized by red, dry, itchy, and scaly patches of abnormal skin growth on the elbows, knees, and/or scalp, which can negatively impact a patient's quality of life and activities of daily living. Both genetic predispositions and environmental factors, which can vary in susceptibility and effect, including infection, stress, medications, and cold temperatures, can lead to the onset of psoriasis and progression of the condition. This review aims to highlight recent advances in understanding the pathophysiology of psoriasis and provide insight into the importance of vaccinations and their role in reducing the risk of infection in psoriasis patients. Vaccination has been shown to reduce the risk of infection in psoriasis patients and those with other autoimmune diseases. Still, vaccination remains limited among autoimmune disease patients. Awareness of the benefits of vaccination needs to be raised among healthcare professionals due to the overarching impact on these patients' lives. The focus of this literature review is to examine the existing data to determine whether vaccination is beneficial for psoriasis patients. Herein, we primarily focus on influenza, pneumococcal, and herpes zoster vaccines and whether immunization benefits or adversely affects psoriasis patients. Overall, we found that most psoriasis and vaccine literature support immunization of this patient population, particularly with non-live attenuated vaccines; however, more studies are needed to fully develop a vaccine recommendation schedule for psoriasis patients.

COVID-19 Vaccines Currently under Preclinical and Clinical Studies, and Associated Antiviral Immune Response

With a death toll of over one million worldwide, the COVID-19 pandemic caused by SARS-CoV-2 has become the most devastating humanitarian catastrophe in recent decades. The fear of acquiring infection and spreading to vulnerable people has severely impacted society's socio-economic status. To put an end to this growing number of infections and deaths as well as to switch from restricted to everyday living, an effective vaccine is desperately needed. As a result, enormous efforts have been made globally to develop numerous vaccine candidates in a matter of months. Currently, over 30 vaccine candidates are under assessment in clinical trials, with several undergoing preclinical studies. Here, we reviewed the major vaccine candidates based on the specific vaccine platform utilized to develop them. We also discussed the immune responses generated by these candidates in humans and preclinical models to determine vaccine safety, immunogenicity, and efficacy. Finally, immune responses induced in recovered COVID-19 patients and their possible vaccine development implications were also briefly reviewed.

Zoster Vaccination in Older Adults: Efficacy and Public Health Implications

Shingles and its most common disabling complication, post-herpetic neuralgia, represent a serious public health challenge in the older population. The decline in the T-cell-mediated immune response to varicella zoster virus after age 50 is clearly associated with increased risk of viral reactivation, causing an acutely painful zoster rash, which may have a severe prodrome of dermatomal pain and persist as seriously debilitating post-herpetic neuralgia well beyond the resolution of the rash. However, new vaccines and adjuvants are being developed and trialed and are now more effective in preventing shingles and the sequelae of post-herpetic neuralgia. Those vaccines that possess the ability to enhance antigen presentation and reverse memory T-cell exhaustion, as well as diminish the immune suppressive effects of regulatory T cells, are most likely to be effective in older adults.

Analysis of Virus and Host Proteomes During Productive HSV-1 and VZV Infection in Human Epithelial Cells

Herpes simplex virus 1 (HSV-1) and varicella-zoster virus (VZV) are two closely related human alphaherpesviruses that persistently infect most adults worldwide and cause a variety of clinically important diseases. Herpesviruses are extremely well adapted to their hosts and interact broadly with cellular proteins to regulate virus replication and spread. However, it is incompletely understood how HSV-1 and VZV interact with the host proteome during productive infection. This study determined the temporal changes in virus and host protein expression during productive HSV-1 and VZV infection in the same cell type. Results demonstrated the temporally coordinated expression of HSV-1 and VZV proteins in infected cells. Analysis of the host proteomes showed that both viruses affected extracellular matrix composition, transcription, RNA processing and cell division. Moreover, the prominent role of epidermal growth factor receptor (EGFR) signaling during productive HSV-1 and VZV infection was identified. Stimulation and inhibition of EGFR leads to increased and decreased virus replication, respectively. Collectively, the comparative temporal analysis of viral and host proteomes in productively HSV-1 and VZV-infected cells provides a valuable resource for future studies aimed to identify target(s) for antiviral therapy development.

Identification and Functional Characterization of a Novel Fc Gamma-Binding Glycoprotein in Rhesus Cytomegalovirus

Receptors recognizing the Fc part of immunoglobulin G (FcγRs) are key determinants in antibody-mediated immune responses. Members of the Herpesviridae interfere with this immune regulatory network by expressing viral FcγRs (vFcγRs). Human cytomegalovirus (HCMV) encodes four distinct vFcγRs that differ with respect to their IgG subtype specificity and their impact on antibody-mediated immune function in vitro The impact of vFcγRs on HCMV pathogenesis and immunomodulation in vivo is not known. The closest evolutionary animal model of HCMV is rhesus CMV (RhCMV) infection of rhesus macaques. To enable the characterization of vFcγR function in this model, we studied IgG binding by RhCMV. We show that lysates of RhCMV-infected cells contain an IgG-binding protein of 30 kDa encoded by the gene Rh05 that is a predicted type I glycoprotein belonging to the RL11 gene family. Upon deletion of Rh05, IgG-Fc binding by RhCMV strain 68-1 is lost, whereas ectopic expression of Rh05 results in IgG binding to transfected cells consistent with Rh05 being a vFcγR. Using a set of reporter cell lines stably expressing human and rhesus FcγRs, we further demonstrate that Rh05 antagonizes host FcγR activation. Compared to Rh05-intact RhCMV, RhCMVΔRh05 showed an increased activation of host FcγR upon exposure of infected cells to IgG from RhCMV-seropositive animals, suggesting that Rh05 protects infected cells from opsonization and IgG-dependent activation of host FcγRs. However, antagonizing host FcγR activation by Rh05 was not required for the establishment and maintenance of infection of RhCMV, even in a seropositive host, as shown by the induction of T cell responses to heterologous antigens expressed by RhCMV lacking the gene region encoding Rh05. In contrast to viral evasion of natural killer cells or T cell recognition, the evasion of antibody-mediated effects does not seem to be absolutely required for infection or reinfection. The identification of the first vFcγR that efficiently antagonizes host FcγR activation in the RhCMV genome will thus permit more detailed studies of this immunomodulatory mechanism in promoting viral dissemination in the presence of natural or vaccine-induced humoral immunity.IMPORTANCE Rhesus cytomegalovirus (RhCMV) offers a unique model for studying human cytomegalovirus (HCMV) pathogenesis and vaccine development. RhCMV infection of nonhuman primates greatly broadened the understanding of mechanisms by which CMVs evade or reprogram T cell and natural killer cell responses in vivo However, the role of humoral immunity and viral modulation of anti-CMV antibodies has not been studied in this model. There is evidence from in vitro studies that HCMVs can evade humoral immunity. By gene mapping and with the help of a novel cell-based reporter assay system we characterized the first RhCMV encoded IgG-Fcγ binding glycoprotein as a potent antagonist of rhesus FcγR activation. We further demonstrate that, unlike evasion of T cell immunity, this viral Fcγ receptor is not required to overcome anti-CMV immunity to establish secondary infections. These findings enable more detailed studies of the in vivo consequences of CMV evasion from IgG responses in nonhuman primate models.

Immune responses to zoster vaccines

There are two licensed herpes zoster vaccines. One is a live vaccine (ZVL) based on an attenuated varicella-zoster virus (VZV). The other is a recombinant vaccine (RZV) based on the VZV glycoprotein E (gE) combined with AS01B, a multicomponent adjuvant system. RZV is superior to ZVL in efficacy, and differs from ZVL in that protection is not diminished by the age of the vaccinee and has not waned significantly during 4 years of follow-up. Immunologic studies demonstrated higher peak memory and persistence of T cell responses in RZV compared with ZVL recipients. RZV recipients also showed development and persistence of polyfunctional T cell responses. Taken together, we conclude that the immunologic data parallel and support the higher efficacy over time of RZV compared with ZVL.

Viral infections in the biologic therapy era

INTRODUCTION

The development of biologic therapies for treating patients with rheumatic, hematologic, or oncological diseases has increased in the last few years, spreading their use in clinical practice. Areas covered: Clinical experience has evidenced substantial risks for some viral infections and/or reactivations such as viral hepatitis, herpetic infections, and other viruses, as a consequence of specific immune pathway blockages. Biological therapies produce a variable risk of reactivation of viral infections, which is particularly uncertain in the case of the most recently introduced agents. Here we make an extensive review of the viral infections associated with the use of biological drugs and provide a series of recommendations for its prevention and management. Expert commentary: To prevent these infections/reactivations, the practitioner must be aware of the infection-risk profile, performing accurate screening during and after the use of any biologic agent. In some instances, expert recommendations are made for some therapies, while in other scenarios recommendations have not yet been defined making experimental and clinical research an essential approach to elucidate multiple issues yet not resolved in this field.

A novel nonlive, adjuvanted herpes zoster subunit vaccine: a report on the emerging clinical data and safety profile

Herpes zoster (HZ) is an acute vesicular dermatitis with a typical dermatomal distribution, caused by the varicella zoster virus (VZV), often preceded and accompanied by prodromal pain or pruritus. HZ may be related to several complications such as postherpetic neuralgia (PHN). The incidence and severity of the disease increase with aging, due to immunosenescence and in particular to the decline of the specific cell-mediated immunity (CMI). The impact of HZ in terms of morbidity and short- and long-term complications, the availability of suboptimal treatment options to date, and the high costs for the diagnostic and clinical-therapeutic management of patients have motivated the search for a new preventive approach through the development of a vaccine. The vaccine currently in use with live-attenuated virus (ZVL) has been shown to be effective in reducing the incidence of HZ, its impact, and the onset of PHN, although the efficacy is lower in older subjects and tends to decrease some years after immunization. A new adjuvanted recombinant subunit vaccine (HZ/su), containing the VZV glycoprotein E (gE) and the AS01B adjuvant system, is now a very promising alternative to ZVL; in several clinical studies, it showed a good safety profile and was able to elicit high immune humoral and cell-mediated responses, both maintained up to 9 years. Furthermore, HZ/su vaccine was effective both in preventing HZ and in reducing the onset of PHN and other complications. HZ/su has been recommended and preferred over ZVL by the Advisory Committee on Immunization Practices (ACIP) for the prevention of HZ and its complications in immunocompetent adults aged ≥50 years, even if already vaccinated with ZVL, through a two-dose schedule. HZ/su has been approved in Canada, USA, Europe, and Japan and is currently being approved in Australia. The aim of this review was to describe the epidemiological data, HZ and PHN risks and their impact on the social life and common life of infected people, and ZVL and HZ/su vaccine development including various clinical trials and efficacy, safety, and tolerability profiles.

Herpes zoster vaccination in systemic lupus erythematosus: the current status

Among the inflammatory rheumatic diseases, SLE is associated with the highest risk of herpes zoster reactivation relative to age. The reported incidence of herpes zoster infection in SLE ranges from 6.4 to 91.4/1000 patient-years, with main risk factors being major organ disease, immunosuppressive and biological therapies. Although herpes zoster in SLE is manageable with anti-viral treatment, complications such as superimposed bacterial infection, post-herpetic neuralgia may ensue. The low rate of herpes zoster vaccination in SLE is related to the lack of awareness, fear of the risk of vaccine-induced infection and disease flare, cost, as well as the lack of explicit recommendations of vaccine use for the paucity of data in immunocompromised and younger subjects. The recent availability of the non-live subunit and inactivated herpes zoster vaccines has provided more opportunities for SLE patients to be protected against this viral infection. More clinical trials are clearly needed in SLE to confirm safety, immunogenicity and efficacy of the herpes zoster vaccines.

Tale of two vaccines: differences in response to herpes zoster vaccines

About one-third of the US population will develop herpes zoster (HZ, commonly known as shingles) over a lifetime, while two-thirds will not. It is not clear exactly why certain people are susceptible to HZ; however, we may be coming closer to an answer. In this issue of the JCI, a study by Levin et al. provides important details concerning pathogenesis of and protection from HZ. The authors characterized differences in the immunologic responses induced by two HZ vaccines, the live attenuated zoster vaccine (ZV) and the more recently developed adjuvanted varicella-zoster virus (VZV) glycoprotein E (gE) subunit herpes zoster vaccine (HZ/su), in vaccine-naive subjects and those previously vaccinated with HZ. The observed differences in responses paralleled the observed clinical protection of the two zoster vaccines, with HZ/su being superior to HZ. Together, these results seem to explain immunologically why the new subunit vaccine outperforms the live vaccine. These differences may also provide clues as to why HZ develops in the first place.

Challenges in adult vaccination

Life-long primary prevention interventions beginning and continuing throughout an individual's lifetime are increasingly seen as key to meeting the global healthcare challenges that accompany demographic changes - a concept referred to as "Healthy aging". In this perspective, vaccination is seen as part of a triad, together with healthy diet and exercise. Current adult vaccine coverage is lower than target vaccination rates in most developed countries, and so vaccine preventable diseases continue to present a substantial burden on health and healthcare resources, especially in older individuals. In part, this is due to lack of knowledge and understanding of the benefits of vaccination, inconsistent recommendations by providers and uncertainties about cost benefits. However, lower vaccine effectiveness in older adults plays a part, and new vaccines with novel characteristics to improve effectiveness in older adults are required. A life-course immunization approach to ensure optimal vaccine uptake across adults of all ages can be expected to reduce morbidity and mortality in later life. To achieve this, greater emphasis on public and healthcare provider education is necessary, based on appropriate economic analyses that demonstrate the overall value of vaccination. This article introduces the technical, economic, political and demographic issues that make establishing effective adult vaccination programs such a difficult, but pressing issue, and outlines some of the steps that are now being taken to address them. Key messages Life-long preventive activities that start and continue throughout life are essential, especially as the world's population is "getting older". This "Healthy aging" approach includes not only healthy diet and physical exercise; vaccination is critical in reducing some infectious diseases and their complications. Many adults, especially older adults (who have lower immunity than younger people) develop infections such as influenza and shingles that could potentially be prevented through vaccination. This review provides a perspective on the challenges in delivering a life-course immunization program. While some vaccines are less effective in older people, newer vaccines have been developed which provide stronger and longer protection in older patients than standard existing vaccines. However, the benefits of vaccination can only be realized if the vaccines are recommended and used. For that purpose, greater education of patients and their healthcare providers is necessary. Better knowledge of vaccines and making sure that all adults are up to date with all their recommended vaccines is an essential part of "Healthy aging". This should prevent not only vaccine-preventable diseases but also reduce the risk of complications in later life.

Shingrix: The New Adjuvanted Recombinant Herpes Zoster Vaccine

OBJECTIVES

To review the immunogenicity, efficacy, and safety of the herpes zoster subunit vaccine (HZ/su) for use in adult patients for the prevention of shingles.

DATA SOURCES

A literature search through PubMed was conducted (June 2008 to October 2017) using the terms shingles vaccine and varicella zoster virus. References from retrieved articles and the prescribing information were also reviewed for any additional material.

STUDY SELECTION/DATA EXTRACTION

The literature search was limited to human studies published in English. Randomized controlled, multicenter trials were reviewed and included to evaluate the safety and efficacy of HZ/su. Literature on the epidemiology and pathology of herpes zoster virus infections and recommendations from the Advisory Committee on Immunization Practices (ACIP) were also reviewed.

DATA SYNTHESIS

HZ/su is a new adjuvanted recombinant vaccine approved by the Food and Drug Administration for the prevention of herpes zoster in adults 50 years of age and older. HZ/su significantly reduced the risk of developing herpes zoster by more than 90% as compared with placebo and displayed a comparable adverse effect profile. The most common local adverse events were injection site pain, redness, and swelling, and the most common systemic adverse events were myalgia, fatigue, and headache. The ACIP recommends the routine use of HZ/su as the preferred vaccine for the prevention of herpes zoster in immunocompetent adults 50 years of age and older.

CONCLUSIONS

Based on published immunogenicity, efficacy, and safety data, as well as the recent recommendations by the ACIP, HZ/su should be included on both hospital and community pharmacy formularies and recommended to all immunocompetent patients older than 50 years to prevent herpes zoster.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Immune checkpoint inhibitors, cell adhesion inhibitors, sphingosine-1-phosphate receptor modulators and proteasome inhibitors)

BACKGROUND

The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) consensus document on the safety of targeted and biological therapies.

AIMS

To review, from an infectious diseases perspective, the safety profile of immune checkpoint inhibitors, LFA-3-targeted agents, cell adhesion inhibitors, sphingosine-1-phosphate receptor modulators and proteasome inhibitors, and to suggest preventive recommendations.

SOURCES

Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family.

CONTENT

T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death (PD)-1/PD-1 ligand 1 (PD-L1)-targeted agents do not appear to intrinsically increase the risk of infection but can induce immune-related adverse effects requiring additional immunosuppression. Although CD4⁺ T-cell lymphopenia is associated with alefacept, no opportunistic infections have been observed. Progressive multifocal leukoencephalopathy (PML) may occur during therapy with natalizumab (anti-α4-integrin monoclonal antibody (mAb)) and efalizumab (anti-CD11a mAb), but no cases have been reported to date with vedolizumab (anti-α4β7 mAb). In patients at high risk for PML (positive anti-JC polyomavirus serology with serum antibody index >1.5 and duration of therapy ≥48 months), the benefit-risk ratio of continuing natalizumab should be carefully considered. Fingolimod induces profound peripheral blood lymphopenia and increases the risk of varicella zoster virus (VZV) infection. Prophylaxis with (val)acyclovir and VZV vaccination should be considered. Proteasome inhibitors also increase the risk of VZV infection, and antiviral prophylaxis with (val)acyclovir is recommended. Anti-Pneumocystis prophylaxis may be considered in myeloma multiple patients with additional risk factors (i.e. high-dose corticosteroids).

IMPLICATIONS

Clinicians should be aware of the risk of immune-related adverse effects and PML in patients receiving immune checkpoint and cell adhesion inhibitors respectively.

Human cytomegalovirus vaccine development: Immune responses to look into vaccine strategy

Human cytomegalovirus (HCMV) causes considerable morbidity and disability in high risk, immunocompromised populations including recipients of solid organ transplants, and fetuses whose immune systems are not yet mature. Vaccines aimed at ameliorating the severity of disease and preventing HCMV infection can be categorized into two main approaches of vaccine design, with one focusing on virus modification and the other on individual antigens. However, no candidates in either class have been successful in achieving durable and protective immunity. Recent studies on the natural immune response provide new insight into HCMV vaccine strategy. In particular, studies have demonstrated that the incorporation of a pentameric complex is necessary for a vaccine to generate the potent neutralizing antibodies often seen in seropositive individuals. This review summarizes recent findings in the development of HCMV vaccines and key considerations that should be taken into vaccine design based on improved understanding of natural HCMV immunity.

A Herpes Simplex Virus Type 2 Deleted for Glycoprotein D Enables Dendritic Cells to Activate CD4+ and CD8+ T Cells

Herpes simplex virus type 2 (HSV-2) is highly prevalent in the human population producing significant morbidity, mainly because of the generation of genital ulcers and neonatal encephalitis. Additionally, HSV-2 infection significantly increases the susceptibility of the host to acquire HIV and promotes the shedding of the latter in the coinfected. Despite numerous efforts to create a vaccine against HSV-2, no licensed vaccines are currently available. A long-standing strategy, based on few viral glycoproteins combined with adjuvants, recently displayed poor results in a Phase III clinical study fueling exploration on the development of mutant HSV viruses that are attenuated in vivo and elicit protective adaptive immune components, such as antiviral antibodies and T cells. Importantly, such specialized antiviral immune components are likely induced and modulated by dendritic cells, professional antigen presenting cells that process viral antigens and present them to T cells. However, HSV interferes with several functions of DCs and ultimately induces their death. Here, we propose that for an attenuated mutant virus to confer protective immunity against HSV in vivo based on adaptive immune components, such virus should also be attenuated in dendritic cells to promote a robust and effective antiviral response. We provide a background framework for this idea, considerations, as well as the means to assess this hypothesis. Addressing this hypothesis may provide valuable insights for the development of novel, safe, and effective vaccines against herpes simplex viruses.

Assessment of the potential public health impact of Herpes Zoster vaccination in Germany

The aim of this study was to compare the public health impact of introducing 2 Herpes Zoster (HZ) vaccines, Zoster Vaccine Live (ZVL) versus a non-live adjuvanted subunit candidate vaccine (HZ/su), in the German population aged 50+ years split into 3 age cohorts, i.e. 50–59, 60–69 and 70+ years, respectively. A multi-cohort static Markov model was developed following age cohorts over their lifetime. Demographic data were obtained from the German federal statistical office. HZ incidence and the proportion of HZ individuals developing post-herpetic neuralgia (PHN) were derived from German specific sources. Age-specific vaccine efficacy and waning rates were based on published clinical trial data. Vaccine coverage for both vaccines was assumed to be 40%, with compliance of the second dose of the HZ/su vaccine of 70%. Sensitivity analyses were performed to assess the robustness of the results. It was estimated that, over the remaining lifetime since vaccination, the HZ/su vaccine would reduce the number of HZ cases by 725,233, 533,162 and 486,794 in the 3 age cohorts, respectively, compared with 198,477, 196,000 and 104,640, using ZVL. The number needed to vaccinate (NNV) to prevent one HZ case ranged from 8 to 11 using the HZ/su vaccine compared with 20 to 50 using ZVL. Corresponding NNV to prevent one PHN case ranged from 39 to 53 using the HZ/su vaccine compared with 94 to 198 using ZVL. Due to the higher, sustained vaccine efficacy, the candidate HZ/su vaccine demonstrated superior public health impact compared with ZVL.

Vaccine profile of herpes zoster (HZ/su) subunit vaccine

INTRODUCTION

Herpes zoster (HZ) causes an often severe and painful rash in older people and may be complicated by prolonged pain (postherpetic neuralgia; PHN) and by dissemination in immune-compromised patients. HZ results from reactivation of latent varicella-zoster virus (VZV) infection, often associated with age-related or other causes of decreased T cell immunity. A live attenuated vaccine boosts this immunity and provides partial protection against HZ, but this decreases with age and declines over 8 years. Areas covered: A new HZ subunit (HZ/su) vaccine combines a key surface VZV glycoprotein (E) with a T cell-boosting adjuvant system (AS01_B) and is administered by two intramuscular injections two months apart. Expert commentary: HZ/su showed excellent efficacy of ~90% in immunocompetent adults ≥50 and ≥70 years of age, respectively, in the ZOE-50 and ZOE-70 phase III controlled trials. Efficacy was unaffected by advancing age and persisted for >3 years. Approximately 9.5% of subjects had severe, but transient (1-2 days) injection site pain, swelling or redness. Compliance with both vaccine doses was high (95%). The vaccine will have a major impact on HZ management. Phase I-II trials showed safety and immunogenicity in severely immunocompromised patients. Phase III trial results are expected soon.

A codon-shuffling method to prevent reversion during production of replication-defective herpesvirus stocks: Implications for herpesvirus vaccines

Herpesviruses establish life-long chronic infections that place infected hosts at risk for severe disease. Herpesvirus genomes readily undergo homologous recombination (HR) during productive replication, often leading to wild-type (WT) reversion during complementation of replication-defective and attenuated viruses via HR with the helper gene provided in trans. To overcome this barrier, we developed a synthetic-biology approach based on a technique known as codon shuffling. Computer-assisted algorithms redistribute codons in a helper gene, thereby eliminating regions of homology, while enabling manipulation of factors such as codon-pair bias and CpG content to effectively titrate helper-gene protein levels. We apply this technique to rescue the replication of a murine gammaherpesvirus engineered with a mutation in the major immediate-early transactivator protein RTA. Complementation with codon-shuffled RTA constructs did not yield any WT revertant virus, a sharp contrast to WT virus contamination frequently observed during complementation with an unmodified helper gene. We further demonstrate the importance of eliminating WT virus contamination in an animal model of gammaherpesvirus lethality. We propose complementation by codon shuffling as a means to produce replication-defective or attenuated viruses. This method has immediate utility for investigating roles of essential genes in viral replication and will better enable future development of herpesvirus vaccines.

Fatal disseminated varicella zoster infection following zoster vaccination in an immunocompromised patient

A 79-year-old man with chronic lymphocytic leukaemia presented with fever and a widespread vesicular rash on 19 November 2014. The patient had not been under immunosuppressive regime for 6 months. He had received a shingles vaccine on 14th October and developed flu-like symptoms after 2 weeks. Intravenous antimicrobial therapy including aciclovir was started. He remained stable with no evidence of systemic involvement. On day 5, he developed respiratory and renal failure that required transfer to intensive care unit. Vesicle fluid, bronchoalveolar lavage and plasma were positive for varicella zoster virus by PCR. Slight clinical improvement allowed extubation on day 16. He subsequently deteriorated and died on day 25. Multiorgan failure was considered the immediate cause of death whereas disseminated varicella zoster infection was stated in the medical certificate as the other condition leading to this outcome. Varicella zoster Oka vaccine strain was detected in vesicle fluid, using PCR.