Vaccine provision: Delivering sustained & widespread use

Proactive vaccination using multiviral Quartet Nanocages to elicit broad anti-coronavirus responses

Defending against future pandemics requires vaccine platforms that protect across a range of related pathogens. Nanoscale patterning can be used to address this issue. Here, we produce quartets of linked receptor-binding domains (RBDs) from a panel of SARS-like betacoronaviruses, coupled to a computationally designed nanocage through SpyTag/SpyCatcher links. These Quartet Nanocages, possessing a branched morphology, induce a high level of neutralizing antibodies against several different coronaviruses, including against viruses not represented in the vaccine. Equivalent antibody responses are raised to RBDs close to the nanocage or at the tips of the nanoparticle's branches. In animals primed with SARS-CoV-2 Spike, boost immunizations with Quartet Nanocages increase the strength and breadth of an otherwise narrow immune response. A Quartet Nanocage including the Omicron XBB.1.5 'Kraken' RBD induced antibodies with binding to a broad range of sarbecoviruses, as well as neutralizing activity against this variant of concern. Quartet nanocages are a nanomedicine approach with potential to confer heterotypic protection against emergent zoonotic pathogens and facilitate proactive pandemic protection.

Discovery and development of COVID-19 vaccine from laboratory to clinic

The world has recently experienced one of the biggest and most severe public health disasters with severe acute respiratory syndrome coronavirus (SARS-CoV-2). SARS-CoV-2 is responsible for the coronavirus disease of 2019 (COVID-19) which is one of the most widespread and powerful infections affecting human lungs. Current figures show that the epidemic had reached 216 nations, where it had killed about 6,438,926 individuals and infected 590,405,710. WHO proclaimed the outbreak of the Ebola virus disease (EVD), in 2014 that killed hundreds of people in West Africa. The development of vaccines for SARS-CoV-2 becomes more difficult due to the viral mutation in its non-structural proteins (NSPs) especially NSP2 and NSP3, S protein, and RNA-dependent RNA polymerase (RdRp). Continuous monitoring of SARS-CoV-2, dynamics of the genomic sequence, and spike protein mutations are very important for the successful development of vaccines with good efficacy. Hence, the vaccine development for SARS-CoV-2 faces specific challenges starting from viral mutation. The requirement of long-term immunity development, safety, efficacy, stability, vaccine allocation, distribution, and finally, its cost is discussed in detail. Currently, 169 vaccines are in the clinical development stage, while 198 vaccines are in the preclinical development stage. The majority of these vaccines belong to the Ps-Protein subunit type which has 54, and the minor BacAg-SPV (Bacterial antigen-spore expression vector) type, at least 1 vaccination. The use of computational methods and models for vaccine development has revolutionized the traditional methods of vaccine development. Further, this updated review highlights the upcoming vaccine development strategies in response to the current pandemic and post-pandemic era, in the field of vaccine development.

Multiviral Quartet Nanocages Elicit Broad Anti-Coronavirus Responses for Proactive Vaccinology

Defending against future pandemics may require vaccine platforms that protect across a range of related pathogens. The presentation of multiple receptor-binding domains (RBDs) from evolutionarily-related viruses on a nanoparticle scaffold elicits a strong antibody response to conserved regions. Here we produce quartets of tandemly-linked RBDs from SARS-like betacoronaviruses coupled to the mi3 nanocage through a SpyTag/SpyCatcher spontaneous reaction. These Quartet Nanocages induce a high level of neutralizing antibodies against several different coronaviruses, including against viruses not represented on the vaccine. In animals primed with SARS-CoV-2 Spike, boost immunizations with Quartet Nanocages increased the strength and breadth of an otherwise narrow immune response. Quartet Nanocages are a strategy with potential to confer heterotypic protection against emergent zoonotic coronavirus pathogens and facilitate proactive pandemic protection.

Vaccine supply chain management: An intelligent system utilizing blockchain, IoT and machine learning

Vaccination offers health, economic, and social benefits. However, three major issues-vaccine quality, demand forecasting, and trust among stakeholders-persist in the vaccine supply chain (VSC), leading to inefficiencies. The COVID-19 pandemic has exacerbated weaknesses in the VSC, while presenting opportunities to apply digital technologies to manage it. For the first time, this study establishes an intelligent VSC management system that provides decision support for VSC management during the COVID-19 pandemic. The system combines blockchain, internet of things (IoT), and machine learning that effectively address the three issues in the VSC. The transparency of blockchain ensures trust among stakeholders. The real-time monitoring of vaccine status by the IoT ensures vaccine quality. Machine learning predicts vaccine demand and conducts sentiment analysis on vaccine reviews to help companies improve vaccine quality. The present study also reveals the implications for the management of supply chains, businesses, and government.

Challenges and lessons from a school-based human papillomavirus (HPV) vaccination program for adolescent girls in a rural Nigerian community

Background

Over 80% of new cervical cancer cases occur in women living in low- and middle-income countries. It is the second highest cause of female cancer deaths in Nigeria. School based vaccination programs are an effective strategy for delivering the HPV vaccine to adolescent girls. This study aims to understand the challenges to implementing school-based HPV vaccination programs, particularly in a remote rural setting where vaccine hesitancy is high.

Methods

A 22- item interviewer administered questionnaire was used to evaluate HPV knowledge and willingness to get the HPV vaccinate among 100 female secondary school students as part of an HPV vaccination pilot in a rural community in Kebbi State, Nigeria. Additionally, semi-structured interviews were used to assess community knowledge and attitudes on cervical cancer and HPV vaccination. Data collected were analyzed thematically to understand challenges and generate lessons for vaccine delivery in the study setting.

Results

Knowledge of HPV and cervical cancer among junior secondary school aged girls was fair with a mean score of 66.05%. For senior secondary school aged girls, the knowledge score ranged from 70 to 100% with a mean of 96.25% indicating good knowledge of HPV and cervical cancer. All participants (n = 100) received the first vaccine dose but due to COVID-19, 33 participants were not able to complete the vaccine dosage within the recommended 6-month schedule. Of the parents who provided consent, none could afford the vaccine out of pocket. Challenges to vaccine delivery included operational costs exacerbated by lack of adequate health workforce and infrastructure in the study setting.

Conclusion

An exploration of sociocultural perspectives and contextual realities is crucial to understanding the complexities of HPV vaccine introduction from the perspective of the target audience, and the local community. Strategies for introducing the HPV vaccine should address community concerns through effective communication, appropriate delivery, and targeted advocacy to make the vaccination program locally relevant. While school-based HPV immunization programs have been shown to be successful, adequate design, planning and monitoring is important. Additionally, considerations must be made to account for the high operational cost of vaccine delivery in rural, hard to reach areas where human resources and infrastructure are limited.

SpySwitch enables pH- or heat-responsive capture and release for plug-and-display nanoassembly

Proteins can be empowered via SpyTag for anchoring and nanoassembly, through covalent bonding to SpyCatcher partners. Here we generate a switchable version of SpyCatcher, allowing gentle purification of SpyTagged proteins. We introduce numerous histidines adjacent to SpyTag’s binding site, giving moderate pH-dependent release. After phage-based selection, our final SpySwitch allows purification of SpyTag- and SpyTag003-fusions from bacterial or mammalian culture by capture at neutral pH and release at pH 5, with purity far beyond His-tag methods. SpySwitch is also thermosensitive, capturing at 4 °C and releasing at 37 °C. With flexible choice of eluent, SpySwitch-purified proteins can directly assemble onto multimeric scaffolds. 60-mer multimerization enhances immunogenicity and we use SpySwitch to purify receptor-binding domains from SARS-CoV-2 and 11 other sarbecoviruses. For these receptor-binding domains we determine thermal resilience (for mosaic vaccine development) and cross-recognition by antibodies. Antibody EY6A reacts across all tested sarbecoviruses, towards potential application against new coronavirus pandemic threats.

The SpyCatcher-SpyTag system allows protein anchoring and nanoassembly. Here, the authors engineer SpySwitch, a dually switchable Catcher which allows gentle purification of SpyTagged proteins prior to downstream applications such as the assembly of virus-like particles.

Vaccine Preventable Zoonotic Diseases: Challenges and Opportunities for Public Health Progress

Zoonotic diseases represent a heavy global burden, causing important economic losses, impacting animal health and production, and costing millions of human lives. The vaccination of animals and humans to prevent inter-species zoonotic disease transmission is an important intervention. However, efforts to develop and implement vaccine interventions to reduce zoonotic disease impacts are often limited to the veterinary and agricultural sectors and do not reflect the shared burden of disease. Multisectoral collaboration, including co-development opportunities for human and animal vaccines, expanding vaccine use to include animal reservoirs such as wildlife, and strategically using vaccines to interrupt complex transmission cycles is needed. Addressing zoonoses requires a multi-faceted One Health approach, wherein vaccinating people and animals plays a critical role.

A 5-year look-back at the notification and management of vaccine supply shortages in Germany

BackgroundUnavailability of vaccines endangers the overall goal to protect individuals and whole populations against infections.MethodsThe German notification system includes the publication of vaccine supply shortages reported by marketing authorisation holders (MAH), information on the availability of alternative vaccine products, guidance for physicians providing vaccinations and an unavailability reporting tool to monitor regional distribution issues.AimThis study provides a retrospective analysis of supply issues and measures in the context of European and global vaccine supply constraints.Resultsbetween October 2015 and December 2020, the 250 notifications concerned all types of vaccines (54 products). Most shortages were caused by increased demand associated with immigration in Germany in 2015 and 2016, new or extended vaccine recommendations, increased awareness, or changes in global immunisation programmes. Shortages of a duration up to 30 days were mitigated using existing storage capacities. Longer shortages, triggered by high demand on a national level, were mitigated using alternative products and re-allocation; in a few cases, vaccines were imported. However, for long lasting supply shortages associated with increased global demand, often occurring in combination with manufacturing issues, few compensatory mechanisms were available. Nevertheless, only few critical incidents were identified: (i) shortage of hexavalent vaccines endangering neonatal immunisation programmes in 2015;(ii) distribution issues with influenza vaccines in 2018; and (iii) unmet demand for pneumococcal and influenza vaccines during the coronavirus disease (COVID)-19 pandemic.ConclusionVaccine product shortages in Germany resemble those present in neighbouring EU states and often reflect increased global demand not matched by manufacturing capacities.

Live-Attenuated VEEV Vaccine Delivered by iDNA Using Microneedles Is Immunogenic in Rabbits

Effective and simple delivery of DNA vaccines remains a key to successful clinical applications. Previously, we developed a novel class of DNA vaccines, sometimes called iDNA, which encodes the whole live-attenuated vaccine viruses. Compared to a standard DNA vaccine, an iDNA vaccine required a low dose to launch a live-attenuated vaccine in vitro or in vivo. The goal of this pilot study was to investigate if iDNA vaccine encoding live-attenuated Venezuelan equine encephalitis virus (VEEV) can be efficiently delivered in vivo by a microneedle device using a single-dose vaccination with naked iDNA plasmid. For this purpose, we used pMG4020 plasmid encoding live-attenuated V4020 vaccine of VEE virus. The V4020 virus contains structural gene rearrangement, as well as attenuating mutations genetically engineered to prevent reversion mutations. The pMG4020 was administered to experimental rabbits by using a hollow microstructured transdermal system (hMTS) microneedle device. No adverse events to vaccination were noted. Animals that received pMG4020 plasmid have successfully seroconverted, with high plaque reduction neutralization test (PRNT) antibody titers, similar to those observed in animals that received V4020 virus in place of the pMG4020 iDNA plasmid. We conclude that naked iDNA vaccine can be successfully delivered in vivo by using a single-dose vaccination with a microneedle device.

Addressing vaccine supply challenges in Europe: Expert industry perspective and recommendations

Shortages of medicines are an increasing concern worldwide. In the European Union (EU), several initiatives have been launched by authorities to address this important public health issue. To contribute in finding solutions, Vaccines Europe (VE), representing 14 vaccine companies operating in Europe, conducted an analysis of the main root causes of vaccine shortages in Europe. Vaccines Europe has identified six main causes of vaccine shortages. Finding solutions will require a concerted effort and dialogue with the involvement of all key stakeholders. In this publication, Vaccines Europe is making a series of recommendations aiming at improving vaccine availability for Europe and beyond.

Responding to Questions from Parents with Vaccine Concerns

INTRODUCTION

Even with the benefits of vaccinations, some parents refuse vaccinations because of the influence of vaccine opponents. The purpose of this article is to identify common vaccine concerns on public forums and address these concerns with scientific evidence, thereby offering pediatric nurse practitioners (PNPs) information on how to respond.

METHOD

Six electronic databases were searched to identify parental concerns regarding vaccines and provide evidence-based responses to each concern.

RESULTS

Some parents are concerned that health care providers do not obtain written informed consent before vaccinating their children. Another common concern is that pharmaceutical companies are solely motivated by financial profits when manufacturing vaccines. Parents also share concerns about vaccine manufacturers' exemption from liability for those who suffer a vaccine-related injury.

DISCUSSION

PNPs are responsible for addressing parents' concerns regarding vaccines and providing the public with correct information. PNPs are in a prime position to influence parental vaccine decision-making positively.

An Overview of Influenza Viruses and Vaccines

Influenza remains one of the major public health concerns because it causes annual epidemics and can potentially instigate a global pandemic. Numerous countermeasures, including vaccines and antiviral treatments, are in use against seasonal influenza infection; however, their effectiveness has always been discussed due to the ongoing resistance to antivirals and relatively low and unpredictable efficiency of influenza vaccines compared to other vaccines. The growing interest in vaccines as a promising approach to prevent and control influenza may provide alternative vaccine development options with potentially increased efficiency. In addition to currently available inactivated, live-attenuated, and recombinant influenza vaccines on the market, novel platforms such as virus-like particles (VLPs) and nanoparticles, and new vaccine formulations are presently being explored. These platforms provide the opportunity to design influenza vaccines with improved properties to maximize quality, efficacy, and safety. The influenza vaccine manufacturing process is also moving forward with advancements relating to egg- and cell-based production, purification processes, and studies into the physicochemical attributes and vaccine degradation pathways. These will contribute to the design of more stable, optimized vaccine formulations guided by contemporary analytical testing methods and via the implementation of the latest advances in the field.

Quality and Safety of Vaccines Manufacturing: An Online Survey on Attitudes and Perceptions of Italian Internet Users

Background: Vaccination is a worldwide public health practice that requires high uptake levels in order to effectively reduce the incidence of vaccine-preventable diseases. The manufacturing of vaccines is a complex process, and little is known about people’s feelings and opinions on that. Our study aimed at investigating perceptions and attitudes of the general population towards the vaccine production process before the availability of COVID-19 vaccines. Methods: We designed a 15-question online survey in the Italian language which was spread via Facebook and an Italian website "Vaccinarsintoscana" between January and May 2020. We performed a descriptive analysis and applied statistical tests to assess differences in the given answers according to participants’ sociodemographic characteristics. Results: The collected responses (135 participants) about the perceptions on vaccine production process were largely positive: not being concerned about the vaccine production (70.3%); believing the vials did not contain harmful substances (75.6%) and considering the precautionary withdrawal of some batches as highly effective (83.7%). In contrast, a less positive perception was found for the question about the conflict of interest between manufacturing companies and the control systems (48.9%). Moreover, people’s perceptions towards the vaccine components (i.e., microorganism, adjuvants and opinion on batches withdrawal) also showed a good level of confidence and trust. Conclusions: Our study highlighted a generally positive attitude towards the vaccine production process and showed people’s confidence in the control systems, safety and high standards of quality of the vaccine production process.

Vaccine Production Process: How Much Does the General Population Know about This Topic? A Web-Based Survey

Background: Vaccine hesitancy has been recognized as a major global health threat by the World Health Organization. Many studies have investigated vaccine safety as a determinant for vaccine hesitancy; however, not much attention has been paid to vaccine production and quality control during the vaccine production process or whether knowledge about this topic may influence vaccine confidence. The aim of this study was to characterize the common knowledge about the vaccine production process. Methods: A freely accessible online questionnaire was developed on Google Modules and disseminated through social networks. A descriptive analysis of the collected answers was performed, and the chi-square test was used to assess significant differences for the sociodemographic characteristics of the study population (age, gender, work or education and training in the healthcare setting, minor offspring). A binary logistic regression model was performed considering these socio-demographic categories as independent variables. Results: The number of collected questionnaire was 135. Most of the participants (127/135, 94.1%) were aware that quality control measures are carried out during manufacturing, although some knowledge gaps emerged in specific aspects of the vaccine production process, without statistically significant differences between age groups. Working in the healthcare setting or being educated in healthcare may be considered predictors for a better understanding that more than 50% of the production time is spent on quality control (AOR = 3.43; 95% CI: 1.84–8.14, p = 0.01) and that considering quality control performed during the vaccine production process is adequate for avoiding contamination (AOR = 7.90; 95% CI: 0.97–64.34; p = 0.05). Conclusions: This study allowed for a characterization of common knowledge about the vaccine production process. It highlighted the need to implement specific strategies to spread correct information about the vaccine production process. This study may contribute to increased confidence and trust in vaccines and vaccination among the general population.

A COVID-19 vaccine candidate using SpyCatcher multimerization of the SARS-CoV-2 spike protein receptor-binding domain induces potent neutralising antibody responses

There is need for effective and affordable vaccines against SARS-CoV-2 to tackle the ongoing pandemic. In this study, we describe a protein nanoparticle vaccine against SARS-CoV-2. The vaccine is based on the display of coronavirus spike glycoprotein receptor-binding domain (RBD) on a synthetic virus-like particle (VLP) platform, SpyCatcher003-mi3, using SpyTag/SpyCatcher technology. Low doses of RBD-SpyVLP in a prime-boost regimen induce a strong neutralising antibody response in mice and pigs that is superior to convalescent human sera. We evaluate antibody quality using ACE2 blocking and neutralisation of cell infection by pseudovirus or wild-type SARS-CoV-2. Using competition assays with a monoclonal antibody panel, we show that RBD-SpyVLP induces a polyclonal antibody response that recognises key epitopes on the RBD, reducing the likelihood of selecting neutralisation-escape mutants. Moreover, RBD-SpyVLP is thermostable and can be lyophilised without losing immunogenicity, to facilitate global distribution and reduce cold-chain dependence. The data suggests that RBD-SpyVLP provides strong potential to address clinical and logistic challenges of the COVID-19 pandemic.

Venezuelan equine encephalitis vaccine with rearranged genome resists reversion and protects non-human primates from viremia after aerosol challenge

Live-attenuated V4020 vaccine for Venezuelan equine encephalitis virus (VEEV) containing attenuating rearrangement of the virus structural genes was evaluated in a non-human primate model for immunogenicity and protective efficacy against aerosol challenge with wild-type VEEV. The genomic RNA of V4020 vaccine virus was encoded in the pMG4020 plasmid under control of the CMV promoter and contained the capsid gene downstream from the glycoprotein genes. It also included attenuating mutations from the VEE TC83 vaccine, with E2-120Arg substitution genetically engineered to prevent reversion mutations. The population of V4020 vaccine virus derived from pMG4020-transfected Vero cells was characterized by next generation sequencing (NGS) and indicated no detectable genetic reversions. Cynomolgus macaques were vaccinated with V4020 vaccine virus. After one or two vaccinations including by intramuscular route, high levels of virus-neutralizing antibodies were confirmed with no viremia or apparent adverse reactions to vaccinations. The protective effect of vaccination was evaluated using an aerosol challenge with VEEV. After challenge, macaques had no detectable viremia, demonstrating a protective effect of vaccination with live V4020 VEEV vaccine.

Key steps in vaccine development

OBJECTIVE

The goal of a vaccine is to prime the immune response so the immune memory can facilitate a rapid response to adequately control the pathogen on natural infection and prevent disease manifestation. This article reviews the main elements that provide for the development of safe and effective vaccines.

DATA SOURCES

Literature covering target pathogen epidemiology, the key aspects of the functioning immune response underwriting target antigen selection, optimal vaccine formulation, preclinical and clinical trial studies necessary to deliver safe and efficacious immunization.

STUDY SELECTIONS

Whole live, inactivated, attenuated, or partial fractionated organism-based vaccines are discussed in respect of the balance of reactogenicity and immunogenicity. The use of adjuvants to compensate for reduced immunogenicity is described. The requirements from preclinical studies, including establishing a proof of principle in animal models, the design of clinical trials with healthy volunteers that lead to licensure and beyond are reviewed.

RESULTS

The 3 vaccine development phases, preclinical, clinical, and post-licensure, integrate the requirements to ensure safety, immunogenicity, and efficacy in the final licensed product. Continuing monitoring of efficacy and safety in the immunized populations is essential to sustain confidence in vaccination programs.

CONCLUSION

In an era of increasing vaccine hesitancy, the need for a better and widespread understanding of how immunization acts to counteract the continuing and changing risks from the pathogenic world is required. This demands a societal responsibility for obligate education on the benefits of vaccination, which as a medical intervention has saved more lives than any other procedure.

Challenges facing vaccinators in the 21st century: results from a focus group qualitative study

Introduction: Barriers to vaccination and the important role of healthcare professionals (HCPs) in influencing immunization decisions made by parents/patients have been well documented. Little information describes challenges that HCPs face in carrying out their role as vaccinators.

Methods: We conducted a focus group study asking HCPs to describe their expectations as frontline vaccinators versus the day-to-day reality they faced. Participants described challenges impacting their ability and motivation as vaccinators, and proposed key solutions to the most important challenges. A total of 75 nurses and physicians (sixteen groups of frontline vaccinators) from the United Kingdom, United States, Germany and India participated in 2 hour focus-group discussions.

Results: There was disconnect between how participants viewed their role in preserving population health when they started their career, and the reality of real-world practice today. Challenges experienced and reflected were similar across professional groups and countries. Low patient-level vaccine knowledge, patient miseducation, untimely vaccine information, frequently changing vaccine schedules, time pressures, lack of centralized record systems, pressure to achieve vaccination targets, and in some instances vaccine costs, all impacted the efficiency and enthusiasm of HCPs. Identified solutions by the same providers included improving patient-level information, equipping HCPs with effective information, and practical ways to reduce the vaccination burden by improved administrative processes and centralized recording coupled with delegating vaccinator roles.

Conclusion: This focus group gives unique insights into needs of HCPs to fulfill their role as vaccinators. Supporting and equipping vaccinators is critical to the continuing success of vaccination programs and the proposed life-course immunization strategy. (Supplementary Appendix 1)

Achieving high uptake of human papillomavirus vaccination in Malaysia through school-based vaccination programme

BACKGROUND

In 2006, 4 years of planning was started by the Ministry of Health, Malaysia (MOH), to implement the HPV (human papillomavirus) vaccination programme. An inter-agency and multi-sectoral collaborations were developed for Malaysia's HPV school-based immunisation programme. It was approved for nationwide school base implementation for 13-year-old girls or first year secondary students in 2010. This paper examines how the various strategies used in the implementation over the last 7 years (2010-2016) that unique to Malaysia were successful in achieving optimal coverage of the target population.

METHODS

Free vaccination was offered to school girls in secondary school (year seven) in Malaysia, which is usually at the age of 13 in the index year. All recipients of the HPV vaccine were identified through school enrolments obtained from education departments from each district in Malaysia. A total of 242,638 girls aged between 12 to 13 years studying in year seven were approached during the launch of the program in 2010. Approximately 230,000 girls in secondary schools were offered HPV vaccine per year by 646 school health teams throughout the country from 2010 to 2016.

RESULTS

Parental consent for their daughters to receive HPV vaccination at school was very high at 96-98% per year of the programme. Of those who provided consent, over 99% received the first dose each year and 98-99% completed the course per year. Estimated population coverage for the full vaccine course, considering also those not in school, is estimated at 83 to 91% per year. Rates of adverse events reports following HPV vaccination were low at around 2 per 100,000 and the majority was injection site reactions.

CONCLUSION

A multisectoral and integrated collaborative structure and process ensured that the Malaysia school-based HPV immunisation programme was successful and sustained through the programme design, planning, implementation and monitoring and evaluation. This is a critical factor contributing to the success and sustainability of the school-based HPV immunisation programme with very high coverage.

Towards improved process efficiency in vaccine innovation: The Vaccine Innovation Cycle as a validated, conceptual stage-gate model

Continuing investments in vaccine innovation are insufficiently translated into market entries of novel vaccines. This innovation paradox is in part caused by stakeholders lacking complete understanding of the complex array of steps necessary for vaccine development and collaboration difficulties between the wide variety of stakeholders involved. Models providing cross-domain understanding can improve collaboration but currently lack both comprehensibility and granularity to enable a prioritized view of activities and criteria. Key opinion leaders (KOLs) were asked to contribute to the definition of a vaccine innovation cycle (VIC). In a first step, 18 KOLs were interviewed on the stages (activities and results) and gates (evaluation criteria and outcomes) of vaccine innovation. This first description of the VIC was subsequently validated and refined through a survey among 46 additional KOLs. The VIC identifies 29 distinct stages and 28 corresponding gates, distributed in ten different but integrated workstreams, and comprehensibly depicted in a circular innovation model. Some stage-gates occur at defined moments, whereas the occurrence and timing of other stage-gates is contingent on a variety of contextual factors. Yet other stage-gates continuously monitor internal and external developments. A gap-overlap analysis of stage-gate criteria demonstrated that 5 out of 11 criteria employed by vaccine developers correspond with criteria employed by competent (regulatory) authorities. The VIC provides a comprehensive overview of stage-gates throughout the value chain of vaccine innovation. Its cyclical nature highlights the importance of synchronizing with unmet needs and market changes, and conceptualizes the difference between incremental and radical vaccine innovation. Knowledge on the gap between internal and external criteria will enhance the viability of newcomers to the field. The VIC can be used by stakeholders to improve understanding and communication in forming collaborative alliances and consortia. Such a boundary-spanning function may contribute to the reduction of process inefficiencies, especially in public-private partnerships.

Engineering a Rugged Nanoscaffold To Enhance Plug-and-Display Vaccination

Nanoscale organization is crucial to stimulating an immune response. Using self-assembling proteins as multimerization platforms provides a safe and immunogenic system to vaccinate against otherwise weakly immunogenic antigens. Such multimerization platforms are generally based on icosahedral viruses and have led to vaccines given to millions of people. It is unclear whether synthetic protein nanoassemblies would show similar potency. Here we take the computationally designed porous dodecahedral i301 60-mer and rationally engineer this particle, giving a mutated i301 (mi3) with improved particle uniformity and stability. To simplify the conjugation of this nanoparticle, we employ a SpyCatcher fusion of mi3, such that an antigen of interest linked to the SpyTag peptide can spontaneously couple through isopeptide bond formation (Plug-and-Display). SpyCatcher-mi3 expressed solubly to high yields in Escherichia coli, giving more than 10-fold greater yield than a comparable phage-derived icosahedral nanoparticle, SpyCatcher-AP205. SpyCatcher-mi3 nanoparticles showed high stability to temperature, freeze-thaw, lyophilization, and storage over time. We demonstrate approximately 95% efficiency coupling to different transmission-blocking and blood-stage malaria antigens. Plasmodium falciparum CyRPA was conjugated to SpyCatcher-mi3 nanoparticles and elicited a high avidity antibody response, comparable to phage-derived virus-like particles despite their higher valency and RNA cargo. The simple production, precise derivatization, and exceptional ruggedness of this nanoscaffold should facilitate broad application for nanobiotechnology and vaccine development.

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).