Search Results (93)

Background/Objectives: mRNA vaccines introduced during the COVID-19 pandemic were a significant step forward in the rapid development and deployment of vaccines in a global pandemic context. These vaccines showed good protective efficacy, but—due to limited breadth of the immune response—they required frequent boosters with manufactured spike sequences that often lagged behind the circulating strains. In order to enhance the breadth, durability, and magnitude of immune responses, we studied the effect of combining priming with an RNA vaccine technology with boosting with protein/adjuvant using a TLR4-agonist based adjuvant. Methods: Specifically, four proprietary adjuvants (EmT4^TM, LiT4Q^TM, MiT4^TM, and AlT4^TM) were investigated in combination with multiple modes of SARS-CoV-2 vaccination (protein, peptide, RNA) for their effectiveness in boosting antibody responses to SARS-CoV-2 spike protein in murine models. Results: Results showed significant improvement in immune response strength and breadth—especially against more distant SARS-CoV-2 variants such as Omicron—when adjuvants were used in combination with boosters following an RNA vaccine prime. Conclusions: The use of novel TLR4 adjuvants in combination with protein or RNA vaccinations presents a promising strategy for improving the efficacy of vaccines in the event of future pandemics, by leveraging rapid response using an RNA vaccine prime and following up with protein/adjuvant-based vaccines to enhance the breadth of immunity. Full article

Background/Objectives: Beak and feather disease virus (BFDV) is the causative agent of psittacine beak and feather disease (PBFD), affecting psittacine birds. There is currently no commercial vaccine or treatment for this disease. This study developed a novel BFDV coat protein mRNA vaccine encapsidated by TMV coat protein to form pseudovirions (PsVs) and tested its immunogenicity alongside BFDV coat protein (CP) subunit and DNA vaccine candidates. Methods: mRNA and BFDV CP subunit vaccine candidates were produced in Nicotiana benthamiana and subsequently purified using PEG precipitation and gradient ultracentrifugation, respectively. The DNA vaccine candidate was produced in E. coli cells harbouring a plasmid with a BFDV1.1mer pseudogenome. Immunogenicity of the vaccine candidates was evaluated in African grey parrot chicks. Results: Successful purification of TMV PsVs harbouring the mRNA vaccine, and of the BFDV-CP subunit vaccine, was confirmed by SDS-PAGE and western blot analysis. TEM analyses confirmed formation of TMV PsVs, while RT-PCR and RT-qPCR cDNA amplification confirmed encapsidation of the mRNA vaccine candidate within TMV particles. Restriction digests verified presence of the BFDV1.1mer genome in the plasmid. Four groups of 5 ten-week-old African grey parrot (Psittacus erithacus) chicks were vaccinated and received two boost vaccinations 2 weeks apart. Blood samples were collected from all four groups on day 14, 28 and 42, and sera were analysed using indirect ELISA, which showed that all vaccine candidates successfully elicited specific anti-BFDV-CP immune responses. The subunit vaccine candidate showed the strongest immune response, indicated by higher binding titres (>6400), followed by the mRNA and DNA vaccine candidates. Conclusions: The candidate vaccines present an important milestone in the search for a protective vaccine against PBFD, and their inexpensive manufacture could considerably aid commercial vaccine development. Full article

The development of vaccines against viral infections has advanced rapidly over the past century, propelled by innovations in laboratory and molecular technologies. These advances have expanded the range of vaccine platforms beyond live-attenuated and inactivated vaccines to include recombinant platforms, such as subunit proteins and virus-like particles (VLPs), and more recently, mRNA-based vaccines, while also enhancing methods for evaluating vaccine performance. Despite these innovations, a persistent challenge remains: the inherent complexity and heterogeneity of immune responses continue to impede efforts to achieve consistently effective and durable protection across diverse populations. Single-cell technologies have emerged as transformative tools for dissecting this immune heterogeneity, providing comprehensive and granular insights into cellular phenotypes, functional states, and dynamic host–pathogen interactions. In this review, we examine how single-cell epigenomic, transcriptomic, proteomic, and multi-omics approaches are being integrated across all stages of vaccine development—from infection-informed discovery to guide vaccine design, to high-resolution evaluation of efficacy, and refinement of cell lines for manufacturing. Through representative studies, we highlight how insights from these technologies contribute to the rational design of more effective vaccines and support the development of personalized vaccination strategies. Full article

RNA-based cancer vaccines have emerged as transformative immunotherapeutic platforms, leveraging advances in mRNA technology and personalized medicine approaches. Recent clinical breakthroughs, particularly the success of mRNA-4157 combined with pembrolizumab in melanoma patients, have demonstrated significant improvements in efficacy, with a 44% reduction in recurrence risk compared to checkpoint inhibitor monotherapy. Breakthrough results from pancreatic cancer vaccines and novel glioblastoma treatments using layered nanoparticle delivery systems mark 2024–2025 as a pivotal period for RNA cancer vaccine development. Current RNA vaccine platforms include conventional mRNA, self-amplifying RNA, trans-amplifying RNA, and emerging circular RNA technologies, with over 120 clinical trials currently underway across various malignancies. Critical advances in delivery optimization include next-generation lipid nanoparticles with tissue-specific targeting and novel nanoengineered systems achieving rapid immune system reprogramming. Manufacturing innovations focus on automated platforms, reducing production timelines from nine weeks to under four weeks for personalized vaccines, while costs remain challenging at over $ 100,000 per patient. Artificial intelligence integration is revolutionizing neoantigen selection through advanced algorithms and CRISPR-enhanced platforms, while regulatory frameworks are evolving with new FDA guidance for therapeutic cancer vaccines. Non-coding RNA applications, including microRNA and long non-coding RNA therapeutics, represent emerging frontiers with potential for enhanced immune modulation. With over 60 candidates in clinical development and the first commercial approvals anticipated by 2029, RNA cancer vaccines are positioned to become cornerstone therapeutics in personalized oncology, offering transformative hope for cancer patients worldwide. Full article

Background: The re-emerging mpox virus (MPXV) has spread to numerous countries and raised global concern. There is an urgent need for a safe and effective mRNA vaccine candidate against MPXV infection. Previously, we developed a penta-component mRNA vaccine that contained five distinct antigen-encoded mRNAs encapsulated within lipid nanoparticles (LNPs). Here, we sought to develop a single-chain mRNA vaccine that encodes antigens derived from both intracellular mature virion (IMV) and extracellular enveloped virion (EEV). Methods: A single-chain mRNA vaccine encoding a fusion protein comprising the ectodomains of M1R (eM1R) and A35R (eA35R) (MPXV^eM1-eA35) was developed and characterized, while an admixed formulation of two individual mRNA-LNPs encoding separate antigens was developed as the control (MPXV^eM1+eA35). Meanwhile, based on the same strategy, we designed a single-chain mRNA vaccine encoding dimeric antigens (MPXV^eM1-eA35-Fc). Mice were immunized with two doses of the candidate vaccines, and both humoral and cellular immune responses were evaluated. The protective efficacy of the candidate vaccines was evaluated based on body weight monitoring and tissue viral load measurement after challenge with vaccinia virus (VACV). Results: Immunization with two doses of MPXV^eM1-eA35 elicited robust levels of neutralizing antibodies and antigen-specific cellular immune response. Importantly, MPXV^eM1-eA35 demonstrated protective efficacy in a VACV challenge mouse model and showed superior capacity in preventing weight loss post-challenge compared to MPXV^eM1+eA35. Similarly, MPXV^eM1-eA35-Fc exhibited comparable or superior immunogenicity and protective efficacy compared to the admixed formulations. Conclusions: The single-chain mRNA vaccine elicited a protective immune response in mice, offering significant advantages in terms of manufacturing processes and quality control. Our single-chain mRNA vaccine platform presents a promising strategy for the next generation design of mpox vaccines and contributes to the mitigation of MPXV endemic worldwide. Full article

With the successful deployment of several mRNA vaccines against SARS-CoV-2, an mRNA vaccine against RSV (respiratory syncytial virus) and a large pipeline of mRNA products against other infectious diseases, cancers and rare diseases, it is important to examine the whole product lifecycle. mRNA technology enables product design, testing and manufacturing systems to be rapidly developed, but these advantages can be lost if other factors that determine public access are not closely considered. This review analyzes key aspects of the mRNA product lifecycle including candidate design, manufacturing, quality systems and product safety and storage. Regulatory thinking is well advanced in some countries but not others, but more thought on the regulation of mRNA vaccines outside of a pandemic situation as well as mRNA therapeutics including individual neoantigen therapies and rare disease treatments is needed. Consumer acceptance—the “social license to operate” around mRNA products—is critical for their uptake, particularly outside of a pandemic. Full article

Background: Respiratory syncytial virus (RSV) and varicella–zoster virus (VZV) pose significant risks to the elderly and individuals with compromised immune systems. In this study, we investigated whether combining RSV and VZV vaccines could reduce the number of vaccination injections, thereby minimizing discomfort for elderly individuals and reducing manufacturing costs. Methods: In this study, we developed two types of combined RSV and VZV mRNA vaccines. Using RSV and VZV mRNA vaccines administered alone as controls, we evaluated the immune response elicited by the combined mRNA vaccines in C57BL/6J mice. Results: The results demonstrated that RSV mRNA, VZV mRNA, and a mixture of both could be effectively encapsulated in lipid nanoparticles (LNPs) with uniform particle sizes. Compared to the administration of either the RSV or VZV mRNA vaccine alone, the delivery of two kinds of mRNA LNP combination formulation—whether directly mixed or encapsulated two mRNAs in the same LNP formulation—elicited comparable IgG titers, neutralization titers, cell-mediated immunity (CMI), and CD4⁺ T-cell responses. Conclusions: In conclusion, this study establishes the feasibility of combining RSV and VZV mRNA-LNP vaccines, laying a solid foundation for clinical trials of combined RSV and VZV vaccines. Full article

Background/Objectives: The development of lipid nanoparticles (LNPs) as delivery platforms for nucleic acids has revolutionised possibilities for both therapeutic and vaccine applications. However, emerging studies highlight challenges in achieving reliable in vitro–in vivo correlation (IVIVC), which delays the translation of experimental findings into clinical applications. This study investigates these potential discrepancies by evaluating the physicochemical properties, in vitro efficacy (across three commonly used cell lines), and in vivo performance (mRNA expression and vaccine efficacy) of four LNP formulations. Methods: LNPs composed of DSPC, cholesterol, a PEGylated lipid, and one of four ionizable lipids (SM-102, ALC-0315, MC3, or C12-200) were manufactured using microfluidics. Results: All formulations exhibited comparable physicochemical properties, as expected (size 70–100 nm, low PDI, near-neutral zeta potential, and high mRNA encapsulation). In vitro studies demonstrated variable LNP-mediated mRNA expression in both immortalised and immune cells, with SM-102 inducing significantly higher protein expression (p < 0.05) than the other formulations in immortalised and immune cells. However, in vivo results revealed that ALC-0315 and SM-102-based LNPs achieved significantly (p < 0.05) higher protein expression without a significant difference between them, while MC3- and C12-200-based LNPs exhibited lower expression levels. As vaccine formulations, all LNPs elicited strong immune responses with no significant differences among them. Conclusions: These findings highlight the complexities of correlating in vitro and in vivo outcomes in LNP development and demonstrate the importance of holistic evaluation strategies to optimise their clinical translation. Full article

Background/Objectives: An overwhelming burden to clinics, herpes zoster (HZ), or shingles, is a painful disease that occurs frequently among aged individuals with a varicella-zoster virus (VZV) infection history. The cause of shingles is the reactivation of dormant VZV in the dorsal root ganglia/cranial nerves of the human body. Patients with HZ experience sharp, intense, electric shock-like pain, which makes their health-related quality of life (HRQoL) extremely low. Methods: Various mRNA constructs were designed based on intracellular organelle-targeting strategies and AI algorithm-guided high-throughput automation platform screening and were then synthesized by in vitro transcription and encapsulated with four-component lipid nanoparticles (LNPs). Immunogenicity was evaluated on a naïve mouse model, long-term mouse model, and VZV-primed mouse model. Safety was evaluated by a modified “nestlet shredding” method for potential adverse effects induced by vaccines. Comparison between muscular and intradermal administrations was conducted using different inoculated approaches as well. Results: The best vaccine candidate, CVG206, showed robust humoral and cellular immune responses, durable immune protection, and the fewest adverse effects. The CVG206 administered intradermally revealed at least threefold higher humoral and cellular immune responses compared to intramuscular vaccination. The manufactured and lyophilized patch of CVG206 demonstrated good thermal stability at 2–8 °C during 9 months of storage. Conclusions: The lyophilized mRNA vaccine CVG206 possesses remarkable immunogenicity, long-term protection, safety, and thermal stability, and its effectiveness could even be further improved by intradermal administration, revealing that CVG206 is a promising vaccine candidate for HZ in future clinical studies. Full article

Background: The COVID-19 pandemic revealed vaccine supply chain (VSC) weaknesses and enabled post-pandemic analysis highlighting the growing importance of supply chain resilience. This study analyzes weaknesses and potentials for VSC resilience from an industry perspective. Insights from this study are aimed at supporting helping managers and policy-makers build a more resilient vaccine supply. Methods: A qualitative semi-structured interview study was conducted with 12 industry experts along the VSC. The interviews were assessed concerning the learnings from the pandemic in a two-step content analysis. Codes were assigned to key VSC concepts and variables and then linked to political, economic, social, technological, legal, and environmental (PESTLE) dimensions. The complex multi-stakeholder supply chain was visualized in a system overview, highlighting main actors, roles, constraints, and resilience. Results: The analysis resulted in 60 codes, categorized into the six PESTLE dimensions and three additional (sub)groups (mRNA, Supply chain resilience, and Solutions). The largest dimension was Economic, with 39 codes, including the Supply chain resilience subgroup. Twelve stakeholder groups were identified, with purchasers, manufacturers, suppliers, developers, and regulatory agencies being the most significant in emergency vaccine manufacturing situations. Conclusions: The system overview demonstrated the VSC as a complex network of actors with unaligned goals rather than a linear supply chain. This study shows that the VSC is characterized by uncertainty due to external factors, like the unpredictability of new emergencies, and internal factors like vaccine demand. The lack of transparency between industry stakeholders exacerbates VSC disruption. We conclude that infrastructures and management practices that enable increased transparency and collaboration between stakeholders hold the greatest potential for strengthening the VSC’s resilience to future pandemics. Full article

In April 2024, a hybrid meeting organized by the WHO, PAHO, and MPP during the World Bank Spring Meetings focused on financing mRNA-based technologies in Low- and Middle-Income Countries (LMICs). This meeting sought to engage multilateral development banks (MDBs) and stakeholders in financing the expansion of vaccine production and enhancing pandemic preparedness. The COVID-19 pandemic underscored the disparities in vaccine production and distribution, highlighting the need for localized production to improve global health equity. The WHO’s mRNA Technology Transfer Programme, initiated in 2021, aims to build local capacity for mRNA vaccine development and manufacturing. Key sessions covered during the meeting include innovative investment models, with MDBs discussing funding instruments and the necessity of an integrated ecosystem for sustainable vaccine manufacturing. Challenges such as technological risks and the need for higher risk appetite were addressed, along with innovative financing mechanisms like blended financing. An analysis of capital and operational expenditures for mRNA vaccine facilities was presented, projecting significant production capacity in LMICs within a decade. Panelists emphasized the need for sustainable R&D investment and shared experiences in securing funding for mRNA technology. The meeting underscored the importance of collaboration, innovative financing, ecosystem development, and public–private partnerships, marking a pivotal step towards advancing mRNA technology in LMICs to tackle global health challenges. Full article

Background: The emergence of more than 40 new infectious diseases since the 1980s has emerged as a serious global health concern, many of which are zoonotic. In response, many international organizations, including the US Centers for Disease Control and Prevention (CDC), the World Health Organization (WHO), and the European Center for Disease Prevention and Control (ECDC), have developed strategies to combat these health threats. The need for rapid vaccine development has been highlighted by Coronavirus disease 2019 (COVID-19), and mRNA technology has shown promise as a platform. While the acceleration of vaccine development has been successful, concerns have been raised about the technical limits, safety, supply, and distribution of vaccines. Objective: This study analyzes the status of vaccine platform development in global pandemics and explores ways to respond to future pandemic crises through an overview of the roles of international organizations and their support programs. It examines the key roles and partnerships of international organizations such as the World Health Organization (WHO), vaccine research and development expertise of the Coalition for Epidemic Preparedness Innovations (CEPI), control of the vaccine supply chain and distribution by the Global Alliance for Vaccines and Immunization (GAVI), and technology transfer capabilities of the International Vaccine Institute (IVI) in supporting the development, production, and supply of vaccine platform technologies for pandemic priority diseases announced by WHO and CEPI and analyzes their vaccine support programs and policies to identify effective ways to rapidly respond to future pandemics caused by emerging infectious diseases. Methods: This study focused on vaccine platform technology and the key roles of international organizations in the pandemic crisis. Literature data on vaccine platform development was collected, compared, and analyzed through national and international literature data search sites, referring to articles, journals, research reports, publications, books, guidelines, clinical trial data, and related reports. In addition, the websites of international vaccine support organizations, such as WHO, CEPI, GAVI, and IVI, were used to examine vaccine support projects, initiatives, and collaborations through literature reviews and case study methods. Results: The COVID-19 pandemic brought focus on the necessity for developing innovative vaccine platforms. Despite initial concerns, the swift integration of cutting-edge development technologies, mass production capabilities, and global collaboration have made messenger RNA (mRNA) vaccines a game-changing technology. As a result of the successful application of novel vaccine platforms, it is important to address the remaining challenges, including technical limits, safety concerns, and equitable global distribution. To achieve this, it is essential to review the regulatory, policy, and support initiatives that have been implemented in response to the COVID-19 pandemic, with particular emphasis on the key stages of vaccine development, production, and distribution, to prepare for future pandemics. An analysis of the status of vaccine development for priority pandemic diseases implies the need for balanced vaccine platform development. Also, international organizations such as WHO, CEPI, GAVI, and IVI play key roles in pandemic preparedness and the development and distribution of preventive vaccines. These organizations collaborated to improve accessibility to vaccines, strengthen the global response to infectious diseases, and address global health issues. The COVID-19 pandemic response demonstrates how the synergistic collaboration of WHO’s standardized guidelines, CEPI’s vaccine research and development expertise, GAVI’s control of the vaccine supply chain and distribution, and IVI’s technology transfer capabilities can be united to create a successful process for vaccine development and distribution. Conclusions: In preparation for future pandemics, a balanced vaccine platform development is essential. It should include a balanced investment in both novel technologies such as mRNA and viral vector-based vaccines and traditional platforms. The goal is to develop vaccine platform technologies that can be applied to emerging infectious diseases efficiently and increase manufacturing and distribution capabilities for future pandemics. Moreover, international vaccine support organizations should play key roles in setting the direction of global networking and preparing for international vaccine support programs to address the limitations of previous pandemic responses. As a result, by transforming future pandemic threats from unpredictable crises to surmountable challenges, it is expected to strengthen global health systems and reduce the social and economic burden of emerging infectious diseases in the long term. Full article

mRNA technology can replace the expensive recombinant technology for every type of protein, making biological drugs more affordable. It can also expedite the entry of new biological drugs, and copies of approved mRNA products can be treated as generic or biosimilar products due to their chemical nature. The introduction of hundreds of new protein drugs have been blocked due to the high cost of recombinant development. The low CAPEX and OPEX associated with mRNA technology bring it within the reach of developing countries that are currently deprived of life-saving biological drugs. In this paper, we advise developers to introduce novel proteins and switch recombinant manufacturing to mRNA delivery, and we further advise regulatory authorities to allow for the approval of copies of mRNA products with less testing. We anticipate that mRNA technology will make protein drugs, such as natural and engineered proteins, monoclonal antibodies, and vaccines, accessible to billions of patients worldwide. Full article

The COVID-19 pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is in its sixth year and is being maintained by the inability of current spike-alone-based COVID-19 vaccines to prevent transmission leading to the continuous emergence of variants and sub-variants of concern (VOCs). This underscores the critical need for next-generation broad-spectrum pan-Coronavirus vaccines (pan-CoV vaccine) to break this cycle and end the pandemic. The development of a pan-CoV vaccine offering protection against a wide array of VOCs requires two key elements: (1) identifying protective antigens that are highly conserved between passed, current, and future VOCs; and (2) developing a safe and efficient antigen delivery system for induction of broad-based and long-lasting B- and T-cell immunity. This review will (1) present the current state of antigen delivery platforms involving a multifaceted approach, including bioinformatics, molecular and structural biology, immunology, and advanced computational methods; (2) discuss the challenges facing the development of safe and effective antigen delivery platforms; and (3) highlight the potential of nucleoside-modified mRNA encapsulated in lipid nanoparticles (LNP) as the platform that is well suited to the needs of a next-generation pan-CoV vaccine, such as the ability to induce broad-based immunity and amenable to large-scale manufacturing to safely provide durable protective immunity against current and future Coronavirus threats. Full article

Background/Objectives: The nucleic acid-based product (NAP) portfolio is expanding continuously and provides safer curative options for many disease indications. Nucleic acid-based products offer several advantages compared to proteins and virus-based products. They represent an emerging field; thus, their quality control and regulatory landscape is evolving to ensure adequate quality and safety. Next-Generation Sequencing (NGS) is mostly recommended for NAP identity testing, and we are leveraging its application for impurity profiling. Methods: We proposed a workflow for the purity assessment of NAPs through short-read Illumina NGS followed by data analysis of mRNA vaccine and pDNA samples. We determined the sequence identity, DNA and RNA contamination, off-target RNA contamination, and poly-A count with the proposed workflow. Results: Our workflow predicted most of the critical quality controls of mRNA vaccine and plasmid DNA samples, especially focusing on the identity and the nucleotide-based impurities. Additionally, NGS data interpretation also assisted in strategic decisions for NAP manufacturing process optimizations. Conclusions: We recommend the adaptation of incremental NGS data by regulatory agencies to identify nucleotide-based impurities in NAPs. Perhaps NGS adaptation under cGMP compliance needs to be deliberated with the regulatory bodies, especially focusing on the methods qualification and validation part, starting from the sample collection, NGS library preparation, NGS run, and its data analysis pipeline. Full article