Development and Delivery Systems of mRNA Vaccines

Effect of vorinostat on protein expression in vitro and in vivo following mRNA lipoplex administration

Previously, we demonstrated that cationic liposomes comprised of N-hexadecyl-N,N-dimethylhexadecan-1-aminium bromide, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine and poly(ethylene glycol) cholesteryl ether induced substantial protein expression both in vitro and in vivo following the administration of mRNA/cationic liposome complexes (mRNA lipoplexes). The present study evaluated the effect of vorinostat, a histone deacetylase inhibitor, on protein expression levels in vitro and in vivo following the administration of mRNA lipoplexes. The half-maximal inhibitory concentration (IC50) values of vorinostat for human cervical carcinoma HeLa and human liver cancer HepG2 cells were determined to be 7.8 and 2.6 µM, respectively, following a 24 h incubation period. Treatment with 1 µM vorinostat resulted in a 2.7-fold increase in luciferase (Luc) activity for HeLa cells and a 1.6-fold increase for HepG2 cells at 24 h post-transfection with firefly Luc (FLuc) mRNA lipoplexes compared with untreated cells. However, treatment with 10 µM vorinostat decreased Luc activity compared with treatment with 1 µM vorinostat. Intravenous injection of Cy5-labeled mRNA lipoplexes into mice resulted in mRNA accumulation primarily in the lungs; however, co-injection with vorinostat at doses of 5 or 25 mg/kg resulted in mRNA accumulation in both the lungs and liver. Furthermore, intravenous injection of FLuc mRNA lipoplexes resulted in high Luc activity in both the lungs and spleen. Nevertheless, co-injection with vorinostat slightly decreased Luc activity in the lungs but not in the spleen. These findings indicated that vorinostat enhances in vitro protein expression from transfected mRNA after treatment with a lower concentration of IC50; however, it does not largely affect in vivo protein expression from the transfected mRNA.

Distinct dynamics of mRNA LNPs in mice and nonhuman primates revealed by in vivo imaging

The characterization of vaccine distribution to relevant tissues after in vivo administration is critical to understanding their mechanisms of action. Vaccines based on mRNA lipid nanoparticles (LNPs) are now being widely considered against infectious diseases and cancer. Here, we used in vivo imaging approaches to compare the trafficking of two LNP formulations encapsulating mRNA following intramuscular administration: DLin-MC3-DMA (MC3) and the recently developed DOG-IM4. The mRNA formulated in DOG-IM4 LNPs persisted at the injection site, whereas mRNA formulated in MC3 LNPs rapidly migrated to the draining lymph nodes. Furthermore, MC3 LNPs induced the fastest increase in blood neutrophil counts after injection and greater inflammation, as shown by IL-1RA, IL-15, CCL-1, and IL-6 concentrations in nonhuman primate sera. These observations highlight the influence of the nature of the LNP on mRNA vaccine distribution and early immune responses.

Noninvasive Transdermal Administration of mRNA Vaccines Encoding Multivalent Neoantigens Effectively Inhibits Melanoma Growth

It is difficult to obtain specific tumor antigens, which is one of the main obstacles in the development of tumor vaccines. The vaccines containing multivalent antigens are thought to be more effective in antitumor therapy. In this study, a mRNA encoding three neoantigens of melanoma were prepared and encapsulated into the mannosylated chitosan-modified ethosomes (EthsMC) to obtain a multivalent mRNA vaccine (MmRV) for transcutaneous immunization (TCI). MmRV can effectively induce maturation of dendritic cells, with a better performance than mRNA of a single neoantigen. TCI patches (TCIPs) loading MmRV or siRNA against PDL1 (siPDL1) were prepared and applied to the skin of melanoma-bearing mice. The results showed that TCIPs significantly increase the levels of TNF-α, IFN-γ, and IL-12 in both plasma and tumor tissues, inhibit tumor growth, as well as promote infiltration of CD4+ and CD8+ T cells in the tumor tissues. Furthermore, the combination of MmRV and siPDL1 showed much better antitumor effects than either monotherapy, suggesting a synergistic effect between the vaccine and PDL1 blocker. In addition, the treatment with the TCIPs did not cause damage to the skin, blood, and vital organs of the mice, showing good biosafety. To the best of our knowledge, this work is the first to construct a noninvasive TCI system containing MmRV and siPDL1, providing a convenient and promising approach for tumor treatment.

Prospects and Challenges in Developing mRNA Vaccines for Infectious Diseases and Oncogenic Viruses

mRNA vaccines have emerged as an optimistic technological platform for vaccine innovation in this new scientific era. mRNA vaccines have dramatically altered the domain of vaccinology by offering a versatile and rapid approach to combating infectious diseases and virus-induced cancers. Clinical trials have demonstrated efficacy rates of 94-95% in preventing COVID-19, and mRNA vaccines have been increasingly recognized as a powerful vaccine platform. Although mRNA vaccines have played an essential role in the COVID-19 pandemic, they still have several limitations; their instability and degradation affect their storage, delivery, and over-all efficiency. mRNA is typically enclosed in a transport mechanism to facilitate its entry into the target cell because it is an unstable and negatively charged molecule. For instance, mRNA that is given using lipid-nanoparticle-based vaccine delivery systems (LNPs) solely enters cells through endocytosis, establishing an endosome without damaging the cell membrane. The COVID-19 pandemic has accelerated the development of mRNA vaccine platforms used to treat and prevent several infectious diseases. This technology has the potential to change the future course of the disease by providing a safe and effective way to combat infectious diseases and cancer. A single-stranded genetic sequence found in mRNA vaccines instructs host cells to produce proteins inside ribosomes to elicit immunological responses and prepare the immune system to fight infections or cancer cells. The potential applications of mRNA vaccine technology are vast and can lead to the development of a preferred vaccine pattern. As a result, a new generation of vaccinations has gradually gained popularity and access to the general population. To adapt the design of an antigen, and even combine sequences from different variations in response to new changes in the viral genome, mRNA vaccines may be used. Current mRNA vaccines provide adequate safety and protection, but the duration of that protection can only be determined if further clinical research is conducted.

Immunoinformatic of novel self-amplifying mRNA vaccine lipid nanoparticle against SARS-CoV-2

We developed innovative self-amplifying mRNA (sa-mRNA) vaccine based on the derivative of S and Nsp3 proteins, which are considered crucial adhering to human host cells. We performed B-cell, Major histocompatibility complex (MHC) I, and II epitope which were merged with the KK and GPGPG linker. We also incorporated 5' cap sequence, Kozak sequence, replicase sequence, 3'/5' UTR, and poly A tail within the vaccine structure. The vaccine structure was subsequently docked and run the molecular dynamic simulation with TLR7 molecules. As the results of immune response simulation, the immune response was accelerated drastically up to >10-fold for immunoglobulin, interferon-γ, interleukin-2, immunoglobulin M (IgM) + immunoglobulin G (IgG) isotype, IgM isotype, and IgG1 isotype in secondary and tertiary dose, whereas natural killer cells, macrophages, and dendritic cells showed relatively high concentrations after the first dose. As our finding, the IgM + IgG, IgG1 + IgG2, and IgM level (induced by sa-mRNA vaccine) ensued three times with two-fold increase in days 25, and 50, then decreased after days 70-150. However, 150-350 days demonstrated constantly in the range of 20,000-21,000.

Seed Train Optimization in Microcarrier-Based Cell Culture Post In Situ Cell Detachment through Scale-Down Hybrid Modeling

Microcarrier-based cell culture is a commonly used method to facilitate the growth of anchorage-dependent cells like MA 104 for antigen manufacturing. However, conventionally, static cell culture is employed for cell propagation before seeding the production bioreactor with microcarriers (MCs). This study demonstrates the effective replacement of the conventional method by serial subculturing on MCs with in situ cell detachment under optimal conditions in closed culture units. This study proves that MA 104 can be subcultured at least five times on Cytodex 1 MC without the need for separating cells and MC after cell harvest. Process parameters impacting cell growth were studied post in situ cell detachment in a scaled-down model. Optimization, using augmented Design of Experiments (DoE) combined with hybrid modeling, facilitated rapid screening of the design space for critical process parameters (CPPs). Optimized conditions included an inoculation density of >16 cells/bead, 3.5-4.5 g/L of Cytodex 1, and a controlled agitation speed, starting at Njs (minimum agitation speed) for the first day with a maximum increase of 25% thereafter. With these design spaces for CPPs, a cell density of 2.6 ± 0.5 × 106 cells/mL was achieved after five days. This refined bioprocess methodology offers a reliable and efficient approach for seed training in stirred tank reactors, which is particularly beneficial for viral vaccine production.

Challenges and advances of the stability of mRNA delivery therapeutics

mRNA therapeutics have garnered significant attention in the biomedical realm, showing immense potential across a spectrum of applications from COVID-19 to cancer treatments. Their ability to trigger precise protein expression, particularly in genome editing, is pivotal in minimizing off-target effects. At the core of mRNA therapy lies a dual-component system, comprising the mRNA itself and a delivery vehicle. The breakthrough success of novel COVID-19 vaccines has catapulted lipid nanoparticles to prominence as the preferred delivery vehicle. However, despite their US FDA approval and efficacy, lipid nanoparticles face a significant challenge: poor stability at room temperature, which limits their applications in various geographic regions with disparities in infrastructure and technology. This review aims to dissect the issue of stability inherent in lipid nanoparticles and other mRNA delivery platforms such as polymer-based materials and protein derivative materials. We herein endeavor to unravel the factors contributing to their instability and explore potential strategies to enhance their stability. By doing so, we provide a comprehensive analysis of the current landscape of mRNA delivery systems, highlighting both their successes and limitations, and paving the way for future advancements in this rapidly evolving field.

Advancements in Vaccine Strategies for Chronic Liver Disease Patients: Navigating Post-COVID Challenges and Opportunities

This review addresses the vital role of vaccinations in managing patients with chronic liver disease (CLD), especially in the context of the post-COVID-19 landscape. The pandemic has highlighted the unique vulnerabilities of CLD patients, including those awaiting liver transplantation and post-transplant individuals, who face heightened risks of infection due to compromised immune responses. Recent advancements in vaccine technology, such as mRNA platforms, novel adjuvants, and advanced delivery systems, have significantly accelerated vaccine development, enhancing both speed and efficacy. Moreover, the emergence of personalized vaccines, tailored to everyone's unique immunological profile, presents new opportunities, particularly for those with chronic conditions. This review synthesizes the current state of evidence regarding vaccine recommendations for CLD patients, focusing on their response to vaccinations and proposing effective strategies to protect this vulnerable group from vaccine-preventable diseases. It also explores the challenges in implementing these strategies and considers the impact of emerging vaccine delivery systems on improving outcomes for CLD patients. The paper aims to provide nuanced guidance on vaccination in the rapidly evolving healthcare landscape, addressing both technological innovations and comprehensive patient care strategies.

Transmission-Blocking Vaccines against Schistosomiasis Japonica

Control of schistosomiasis japonica, endemic in Asia, including the Philippines, China, and Indonesia, is extremely challenging. Schistosoma japonicum is a highly pathogenic helminth parasite, with disease arising predominantly from an immune reaction to entrapped parasite eggs in tissues. Females of this species can generate 1000-2200 eggs per day, which is about 3- to 15-fold greater than the egg output of other schistosome species. Bovines (water buffalo and cattle) are the predominant definitive hosts and are estimated to generate up to 90% of parasite eggs released into the environment in rural endemic areas where these hosts and humans are present. Here, we highlight the necessity of developing veterinary transmission-blocking vaccines for bovines to better control the disease and review potential vaccine candidates. We also point out that the approach to producing efficacious transmission-blocking animal-based vaccines before moving on to human vaccines is crucial. This will result in effective and feasible public health outcomes in agreement with the One Health concept to achieve optimum health for people, animals, and the environment. Indeed, incorporating a veterinary-based transmission vaccine, coupled with interventions such as human mass drug administration, improved sanitation and hygiene, health education, and snail control, would be invaluable to eliminating zoonotic schistosomiasis.

Biomaterials for Drug Delivery and Human Applications

Biomaterials embody a groundbreaking paradigm shift in the field of drug delivery and human applications. Their versatility and adaptability have not only enriched therapeutic outcomes but also significantly reduced the burden of adverse effects. This work serves as a comprehensive overview of biomaterials, with a particular emphasis on their pivotal role in drug delivery, classifying them in terms of their biobased, biodegradable, and biocompatible nature, and highlighting their characteristics and advantages. The examination also delves into the extensive array of applications for biomaterials in drug delivery, encompassing diverse medical fields such as cancer therapy, cardiovascular diseases, neurological disorders, and vaccination. This work also explores the actual challenges within this domain, including potential toxicity and the complexity of manufacturing processes. These challenges emphasize the necessity for thorough research and the continuous development of regulatory frameworks. The second aim of this review is to navigate through the compelling terrain of recent advances and prospects in biomaterials, envisioning a healthcare landscape where they empower precise, targeted, and personalized drug delivery. The potential for biomaterials to transform healthcare is staggering, as they promise treatments tailored to individual patient needs, offering hope for improved therapeutic efficacy, fewer side effects, and a brighter future for medical practice.

Innovative Strategies to Enhance mRNA Vaccine Delivery and Effectiveness: Mechanisms and Future Outlook

The creation of mRNA vaccines has transformed the area of vaccination and allowed for the production of COVID-19 vaccines with previously unheard-of speed and effectiveness. The development of novel strategies to enhance the delivery and efficiency of mRNA vaccines has been motivated by the ongoing constraints of the present mRNA vaccine delivery systems. In this context, intriguing methods to get beyond these restrictions include lipid nanoparticles, self-amplifying RNA, electroporation, microneedles, and cell-targeted administration. These innovative methods could increase the effectiveness, safety, and use of mRNA vaccines, making them more efficient, effective, and broadly available. Additionally, mRNA technology may have numerous and far-reaching uses in the field of medicine, opening up fresh avenues for the diagnosis and treatment of disease. This paper gives an overview of the existing drawbacks of mRNA vaccine delivery techniques, the creative solutions created to address these drawbacks, and their prospective public health implications. The development of mRNA vaccines for illnesses other than infectious diseases and creating scalable and affordable manufacturing processes are some of the future directions for research in this area that are covered in this paper.

Advancing personalized medicine in brain cancer: exploring the role of mRNA vaccines

Advancing personalized medicine in brain cancer relies on innovative strategies, with mRNA vaccines emerging as a promising avenue. While the initial use of mRNA vaccines was in oncology, their stunning success in COVID-19 resulted in widespread attention, both positive and negative. Regardless of politically biased opinions, which relate more to the antigenic source than form of delivery, we feel it is important to objectively review this modality as relates to brain cancer. This class of vaccines trigger robust immune responses through MHC-I and MHC-II pathways, in both prophylactic and therapeutic settings. The mRNA platform offers advantages of rapid development, high potency, cost-effectiveness, and safety. This review provides an overview of mRNA vaccine delivery technologies, tumor antigen identification, combination therapies, and recent therapeutic outcomes, with a particular focus on brain cancer. Combinatorial approaches are vital to maximizing mRNA cancer vaccine efficacy, with ongoing clinical trials exploring combinations with adjuvants and checkpoint inhibitors and even adoptive cell therapy. Efficient delivery, neoantigen identification, preclinical studies, and clinical trial results are highlighted, underscoring mRNA vaccines' potential in advancing personalized medicine for brain cancer. Synergistic combinatorial therapies play a crucial role, emphasizing the need for continued research and collaboration in this area.

Deciphering the Immunogenicity of Monkeypox Proteins for Designing the Potential mRNA Vaccine

The Monkeypox virus (MPXV), an orthopox virus, is responsible for monkeypox in humans, a zoonotic disease similar to smallpox. This infection first appeared in the 1970s in humans and then in 2003, after which it kept on spreading all around the world. To date, various antivirals have been used to cure this disease, but now, MPXV has developed resistance against these, thus increasing the need for an alternative cure for this deadly disease. In this study, we devised a reverse vaccinology approach against MPXV using a messenger RNA (mRNA) vaccine by pinning down the antigenic proteins of this virus. By using bioinformatic tools, we predicted prospective immunogenic B and T lymphocyte epitopes. Based on cytokine inducibility score, nonallergenicity, nontoxicity, antigenicity, and conservancy, the final epitopes were selected. Our analysis revealed the stable structure of the mRNA vaccine and its efficient expression in host cells. Furthermore, strong interactions were demonstrated with toll-like receptors 2 (TLR2) and 4 (TLR4) according to the molecular dynamic simulation studies. The in silico immune simulation analyses revealed an overall increase in the immune responses following repeated exposure to the designed vaccine. Based on our findings, the vaccine candidate designed in this study has the potential to be tested as a promising novel mRNA therapeutic vaccine against MPXV infection.

Spleen SORT LNP Generated in situ CAR T Cells Extend Survival in a Mouse Model of Lymphoreplete B Cell Lymphoma

Chimeric Antigen Receptor (CAR) T cell immunotherapy is revolutionizing treatment for patients suffering from B-cell lymphoma (BL). However, the current method of CAR T cell production is complicated and expensive, requiring collection of patient blood to enrich the T cell population, ex vivo engineering/activation, and quality assessment before the patient can receive the treatment. Herein we leverage Spleen Selective ORgan Targeted (SORT) Lipid Nanoparticles (LNPs) to produce CAR T cells in situ and bypass the extensive and laborious process currently used. Optimized Spleen SORT LNPs containing 10 % 18 : 1 PA transfected CD3+, CD8+, and CD4+ T cells in wild-type mice. Spleen SORT LNPs delivered Cre recombinase mRNA and CAR encoding mRNA to T cells in reporter mice and in a lymphoreplete B cell lymphoma model (respectively) after intravenous injection without the need for active targeting ligands. Moreover, in situ CAR T cells increased the overall survival of mice with a less aggressive form of B cell lymphoma. In addition, in situ transfected CAR T cells reduced tumor metastasis to the liver by increasing tumor infiltrating lymphocytes. Overall, these results offer a promising alternative method for CAR T cell production with pre-clinical potential to treat hematological malignancies.

Clinical Analysis and Applications of mRNA Vaccines in Infectious Diseases and Cancer Treatment

Vaccination, for centuries, has been a potent preventive technique to treat morbidities. The messenger RNA (mRNA) vaccine technology is an innovative biomedical approach utilized in developing antigen-specific vaccines that can generate adaptive immune responses, triggering both humoral and cellular immunity to enhance the body's defense against specific infections. This review provides a comprehensive, comparative analysis of mRNA vaccine technology and conventional vaccines by focusing on the structures, components, and classifications. An exploratory analysis of the similarities and differences between mRNA vaccine technology and live-attenuated vaccines highlights the mechanisms by which mRNA vaccines elicit immune responses. This review extensively discusses the production, stability, synthesis, and delivery processes associated with mRNA vaccines, showcasing the advancements and technological superiority of this approach over conventional vaccine technologies. Additionally, the potential of mRNA vaccine technology as a potent alternative for the development of vaccine candidates targeting HIV and cancer is examined.

Immunotherapy: cancer immunotherapy and its combination with nanomaterials and other therapies

Immunotherapy is a new type of tumor treatment after surgery, radiotherapy and chemotherapy, and can be used to manage and destroy tumor cells through activating or strengthening the immune response. Immunotherapy has the benefits of a low recurrence rate and high specificity compared to traditional treatment methods. Immunotherapy has developed rapidly in recent years and has become a research hotspot. Currently, chimeric antigen receptor T-cell immunotherapy and immune checkpoint inhibitors are the most effective tumor immunotherapies in clinical practice. While tumor immunotherapy brings hope to patients, it also faces some challenges and still requires continuous research and progress. Combination therapy is the future direction of anti-tumor treatment. In this review, the main focus is on an overview of the research progress of immune checkpoint inhibitors, cellular therapies, tumor vaccines, small molecule inhibitors and oncolytic virotherapy in tumor treatment, as well as the combination of immunotherapy with other treatments.

The clinical progress and challenges of mRNA vaccines

Owing to the breakthroughs in the prevention and control of the COVID-19 pandemic, messenger RNA (mRNA)-based vaccines have emerged as promising alternatives to conventional vaccine approaches for infectious disease prevention and anticancer treatments. Advantages of mRNA vaccines include flexibility in designing and manipulating antigens of interest, scalability in rapid response to new variants, ability to induce both humoral and cell-mediated immune responses, and ease of industrialization. This review article presents the latest advances and innovations in mRNA-based vaccines and their clinical translations in the prevention and treatment of infectious diseases or cancers. We also highlight various nanoparticle delivery platforms that contribute to their success in clinical translation. Current challenges related to mRNA immunogenicity, stability, and in vivo delivery and the strategies for addressing them are also discussed. Finally, we provide our perspectives on future considerations and opportunities for applying mRNA vaccines to fight against major infectious diseases and cancers. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Biology-Inspired Nanomaterials > Lipid-Based Structures.

Signal detection of COVID-19 vaccines adverse events using spontaneous reports from South Korea

PURPOSE

Studies on the detection of COVID-19 vaccine signals in South Korea are insufficient. Therefore, to investigate adverse events (AEs) that might be associated with COVID-19 vaccines, signals were detected using spontaneous reports from South Korea. We compared the signals with the vaccine insert lists of the regulators in the four countries.

METHODS

Spontaneous reports from 62 sites were collected by the National Medical Center between January 2013 and May 2022. A descriptive analysis of AEs associated with COVID-19 vaccines (Pfizer, Moderna, AstraZeneca, and Janssen) was performed, and the proportional reporting ratio, reporting odds ratio, and information component were calculated. We performed five analyses, with five cases and one control group.

RESULTS

During the study period, 68 355 cases were reported, of which 12 485 were COVID-19 vaccine AEs. Injection site pain (2198 cases, 17.6%), myalgia (1552 cases, 12.4%), headache (1145 cases, 9.2%), pyrexia (1003 cases, 8.0%), and fatigue (735 cases, 5.9%) were frequently reported. When comparing all COVID-19 vaccines with other viral vaccines, 20 signals were detected, of which cachexia, dyspepsia, abdominal discomfort, and mood swings were not listed on the vaccine inserts in all four countries. Overall, 20, 17, 29, and 9 signals were detected in vaccines developed by Pfizer, Moderna, AstraZeneca, and Janssen, respectively.

CONCLUSIONS

Based on a disproportionate analysis of COVID-19 vaccine AEs using spontaneous reports from South Korea, different signals were detected for each vaccine manufacturer.

Lipid nanoparticle-based mRNA delivery systems for cancer immunotherapy

Cancer immunotherapy, which harnesses the power of the immune system, has shown immense promise in the fight against malignancies. Messenger RNA (mRNA) stands as a versatile instrument in this context, with its capacity to encode tumor-associated antigens (TAAs), immune cell receptors, cytokines, and antibodies. Nevertheless, the inherent structural instability of mRNA requires the development of effective delivery systems. Lipid nanoparticles (LNPs) have emerged as significant candidates for mRNA delivery in cancer immunotherapy, providing both protection to the mRNA and enhanced intracellular delivery efficiency. In this review, we offer a comprehensive summary of the recent advancements in LNP-based mRNA delivery systems, with a focus on strategies for optimizing the design and delivery of mRNA-encoded therapeutics in cancer treatment. Furthermore, we delve into the challenges encountered in this field and contemplate future perspectives, aiming to improve the safety and efficacy of LNP-based mRNA cancer immunotherapies.

Recent Advances in Messenger Ribonucleic Acid (mRNA) Vaccines and Their Delivery Systems: A Review

Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use authorization of the two covid-19 mRNA vaccines, BNT162b2 and mRNA-1273, is a significant achievement in the history of vaccine development. Because they are generated in a cell-free environment using the in vitro transcription (IVT) process, mRNA vaccines are risk-free. Moreover, chemical modifications to the mRNA molecule, such as cap structures and changed nucleosides, have proved critical in overcoming immunogenicity concerns, achieving sustained stability, and achieving effective, accurate protein production in vivo. Several vaccine delivery strategies (including protamine, lipid nanoparticles (LNPs), polymers, nanoemulsions, and cell-based administration) were also optimized to load and transport RNA into the cytosol. LNPs, which are composed of a cationic or a pH-dependent ionizable lipid layer, a polyethylene glycol (PEG) component, phospholipids, and cholesterol, are the most advanced systems for delivering mRNA vaccines. Moreover, modifications of the four components that make up the LNPs showed to increase vaccine effectiveness and reduce side effects. Furthermore, the introduction of biodegradable lipids improved LNP biocompatibility. Furthermore, mRNA-based therapies are expected to be effective treatments for a variety of refractory conditions, including infectious diseases, metabolic genetic diseases, cancer, cardiovascular and cerebrovascular diseases. Therefore, the present review aims to provide the scientific community with up-to-date information on mRNA vaccines and their delivery systems.

Advancements in the development of nucleic acid vaccines for syphilis prevention and control

Syphilis, a chronic systemic sexually transmitted disease, is caused by the bacterium Treponema pallidum (T. pallidum). Currently, syphilis remains a widespread infectious disease with significant disease burden in many countries. Despite the absence of identified penicillin-resistant strains, challenges in syphilis treatment persist due to penicillin allergies, supply issues, and the emergence of macrolide-resistant strains. Vaccines represent the most cost-effective strategy to prevent and control the syphilis epidemic. In light of the ongoing global coronavirus disease 2019 (COVID-19) pandemic, nucleic acid vaccines have gained prominence in the field of vaccine research and development, owing to their superior efficiency compared to traditional vaccines. This review summarizes the current state of the syphilis epidemic and the preliminary findings in T. pallidum nucleic acid vaccine research, discusses the challenges associated with the development of T. pallidum nucleic acid vaccines, and proposes strategies and measures for future T. pallidum vaccine development.

mRNA vaccine in cancer therapy: Current advance and future outlook

Messenger ribonucleic acid (mRNA) vaccines are a relatively new class of vaccines that have shown great promise in the immunotherapy of a wide variety of infectious diseases and cancer. In the past 2 years, SARS-CoV-2 mRNA vaccines have contributed tremendously against SARS-CoV2, which has prompted the arrival of the mRNA vaccine research boom, especially in the research of cancer vaccines. Compared with conventional cancer vaccines, mRNA vaccines have significant advantages, including efficient production of protective immune responses, relatively low side effects and lower cost of acquisition. In this review, we elaborated on the development of cancer vaccines and mRNA cancer vaccines, as well as the potential biological mechanisms of mRNA cancer vaccines and the latest progress in various tumour treatments, and discussed the challenges and future directions for the field.

Protection against Severe Illness versus Immunity-Redefining Vaccine Effectiveness in the Aftermath of COVID-19

Anti-SARS-CoV-2 vaccines have played a pivotal role in reducing the risk of developing severe illness from COVID-19, thus helping end the COVID-19 global public health emergency after more than three years. Intriguingly, as SARS-CoV-2 variants emerged, individuals who were fully vaccinated did get infected in high numbers, and viral loads in vaccinated individuals were as high as those in the unvaccinated. However, even with high viral loads, vaccinated individuals were significantly less likely to develop severe illness; this begs the question as to whether the main effect of anti-SARS-CoV-2 vaccines is to confer protection against severe illness or immunity against infection. The answer to this question is consequential, not only to the understanding of how anti-SARS-CoV-2 vaccines work, but also to public health efforts against existing and novel pathogens. In this review, we argue that immune system sensitization-desensitization rather than sterilizing immunity may explain vaccine-mediated protection against severe COVID-19 illness even when the SARS-CoV-2 viral load is high. Through the lessons learned from COVID-19, we make the case that in the disease's aftermath, public health agencies must revisit healthcare policies, including redefining the term "vaccine effectiveness."

Recent Advancement in mRNA Vaccine Development and Applications

Messenger RNA (mRNA) vaccine development for preventive and therapeutic applications has evolved rapidly over the last decade. The mRVNA vaccine has proven therapeutic efficacy in various applications, including infectious disease, immunotherapy, genetic disorders, regenerative medicine, and cancer. Many mRNA vaccines have made it to clinical trials, and a couple have obtained FDA approval. This emerging therapeutic approach has several advantages over conventional methods: safety; efficacy; adaptability; bulk production; and cost-effectiveness. However, it is worth mentioning that the delivery to the target site and in vivo degradation and thermal stability are boundaries that can alter their efficacy and outcomes. In this review, we shed light on different types of mRNA vaccines, their mode of action, and the process to optimize their development and overcome their limitations. We also have explored various delivery systems focusing on the nanoparticle-mediated delivery of the mRNA vaccine. Generally, the delivery system plays a vital role in enhancing mRNA vaccine stability, biocompatibility, and homing to the desired cells and tissues. In addition to their function as a delivery vehicle, they serve as a compartment that shields and protects the mRNA molecules against physical, chemical, and biological activities that can alter their efficiency. Finally, we focused on the future considerations that should be attained for safer and more efficient mRNA application underlining the advantages and disadvantages of the current mRNA vaccines.

Applications of advances in mRNA-based platforms as therapeutics and diagnostics in reproductive technologies

The recent COVID-19 pandemic led to many drastic changes in not only society, law, economics, but also in science and medicine, marking for the first time when drug regulatory authorities cleared for use mRNA-based vaccines in the fight against this outbreak. However, while indeed representing a novel application of such technology in the context of vaccination medicine, introducing RNA into cells to produce resultant molecules (proteins, antibodies, etc.) is not a novel principle. It has been common practice to introduce/inject mRNA into oocytes and embryos to inhibit, induce, and identify several factors in a research context, while such aspects have also been proposed as potential therapeutic and diagnostic applications to combat infertility in humans. Herein, we describe key areas where mRNA-based platforms have thus far represented potential areas of clinical applications, describing the advantages and limitations of such applications. Finally, we also discuss how recent advances in mRNA-based platforms, driven by the recent pandemic, may stand to benefit the treatment of infertility in humans. We also present brief future directions as to how we could utilise recent and current advancements to enhance RNA therapeutics within reproductive biology, specifically with relation to oocyte and embryo delivery.

From lab to mass production: a policy for enabling the licensing of mRNA vaccines

Using the South African vaccine technology transfer hub supported by the WHO as an example, we show that the know-how needed to move mRNA vaccines from prototype to mass-production acts as an invisible barrier to market entry of mRNA vaccines. Overcoming this barrier relies on scarce human capital. In view of this scarcity and in preparation for the next pandemic, we propose broadening the scope of an existing WHO program, the WHO Academy, so that it coordinates knowledge diffusion initiatives by forming a systematized repository of know-how and a register of experts. As we explain, this proposal has an advantage in overcoming barriers to entry over current approaches of know-how acquisition.

Efficient mRNA Delivery with mRNA Lipoplexes Prepared Using a Modified Ethanol Injection Method

Messenger RNA (mRNA)-based therapies are a novel class of therapeutics used in vaccination and protein replacement therapies for monogenic diseases. Previously, we developed a modified ethanol injection (MEI) method for small interfering RNA (siRNA) transfection, in which cationic liposome/siRNA complexes (siRNA lipoplexes) were prepared by mixing a lipid-ethanol solution with a siRNA solution. In this study, we applied the MEI method to prepare mRNA lipoplexes and evaluated the in vitro and in vivo protein expression efficiencies. We selected six cationic lipids and three neutral helper lipids to generate 18 mRNA lipoplexes. These were composed of cationic lipids, neutral helper lipids, and polyethylene glycol-cholesteryl ether (PEG-Chol). Among them, mRNA lipoplexes containing N-hexadecyl-N,N-dimethylhexadecan-1-aminium bromide (DC-1-16) or 11-((1,3-bis(dodecanoyloxy)-2-((dodecanoyloxy)methyl) propan-2-yl) amino)-N,N,N-trimethyl-11-oxoundecan-1-aminium bromide (TC-1-12) with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and PEG-Chol exhibited high protein expression in cells. Furthermore, mRNA lipoplexes composed of DC-1-16, DOPE, and PEG-Chol exhibited high protein expression in the lungs and spleen of mice after systemic injection and induced high antigen-specific IgG1 levels upon immunization. These results suggest that the MEI method can potentially increase the efficiency of mRNA transfection, both in vitro and in vivo.

Lipid Nanoparticles as Promising Carriers for mRNA Vaccines for Viral Lung Infections

In recent years, there has been an increase in deaths due to infectious diseases, most notably in the context of viral respiratory pathogens. Consequently, the focus has shifted in the search for new therapies, with attention being drawn to the use of nanoparticles in mRNA vaccines for targeted delivery to improve the efficacy of these vaccines. Notably, mRNA vaccine technologies denote as a new era in vaccination due to their rapid, potentially inexpensive, and scalable development. Although they do not pose a risk of integration into the genome and are not produced from infectious elements, they do pose challenges, including exposing naked mRNAs to extracellular endonucleases. Therefore, with the development of nanotechnology, we can further improve their efficacy. Nanoparticles, with their nanometer dimensions, move more freely in the body and, due to their small size, have unique physical and chemical properties. The best candidates for vaccine mRNA transfer are lipid nanoparticles (LNPs), which are stable and biocompatible and contain four components: cationic lipids, ionizable lipids, polyethylene glycols (PEGs), and cholesterol, which are used to facilitate cytoplasmic mRNA delivery. In this article, the components and delivery system of mRNA-LNP vaccines against viral lung infections such as influenza, coronavirus, and respiratory syncytial virus are reviewed. Moreover, we provide a succinct overview of current challenges and potential future directions in the field.

An effective live-attenuated Zika vaccine candidate with a modified 5' untranslated region

Zika virus (ZIKV) is a mosquito-transmitted flavivirus that has caused devastating congenital Zika syndrome (CZS), including microcephaly, congenital malformation, and fetal demise in human newborns in recent epidemics. ZIKV infection can also cause Guillain-Barré syndrome (GBS) and meningoencephalitis in adults. Despite intensive research in recent years, there are no approved vaccines or antiviral therapeutics against CZS and adult Zika diseases. In this report, we developed a novel live-attenuated ZIKV strain (named Z7) by inserting 50 RNA nucleotides (nt) into the 5' untranslated region (UTR) of a pre-epidemic ZIKV Cambodian strain, FSS13025. We used this particular ZIKV strain as it is attenuated in neurovirulence, immune antagonism, and mosquito infectivity compared with the American epidemic isolates. Our data demonstrate that Z7 replicates efficiently and produces high titers without causing apparent cytopathic effects (CPE) in Vero cells or losing the insert sequence, even after ten passages. Significantly, Z7 induces robust humoral and cellular immune responses that completely prevent viremia after a challenge with a high dose of an American epidemic ZIKV strain PRVABC59 infection in type I interferon (IFN) receptor A deficient (Ifnar1-/-) mice. Moreover, adoptive transfer of plasma collected from Z7 immunized mice protects Ifnar1-/- mice from ZIKV (strain PRVABC59) infection. These results suggest that modifying the ZIKV 5' UTR is a novel strategy to develop live-attenuated vaccine candidates for ZIKV and potentially for other flaviviruses.

mRNA melanoma vaccine revolution spurred by the COVID-19 pandemic

The advent of mRNA vaccines represents a significant advance in the field of vaccinology. While several vaccine approaches (mRNA, DNA, recombinant protein, and viral-vectored vaccines) had been investigated at the start of the COVID-19 pandemic, mRNA vaccines quickly gained popularity due to superior immunogenicity at a low dose, strong safety/tolerability profiles, and the possibility of rapid vaccine mass manufacturing and deployment to rural regions. In addition to inducing protective neutralizing antibody responses, mRNA vaccines can also elicit high-magnitude cytotoxic T-cell responses comparable to natural viral infections; thereby, drawing significant interest from cancer immunotherapy experts. This mini-review will highlight key developmental milestones and lessons we have learned from mRNA vaccines during the COVID-19 pandemic, with a specific emphasis on clinical trial data gathered so far for mRNA vaccines against melanoma and other forms of cancer.

The mRNA Vaccine Technology Era and the Future Control of Parasitic Infections

Despite intensive long-term efforts, with very few exceptions, the development of effective vaccines against parasitic infections has presented considerable challenges, given the complexity of parasite life cycles, the interplay between parasites and their hosts, and their capacity to escape the host immune system and to regulate host immune responses. For many parasitic diseases, conventional vaccine platforms have generally proven ill suited, considering the complex manufacturing processes involved and the costs they incur, the inability to posttranslationally modify cloned target antigens, and the absence of long-lasting protective immunity induced by these antigens. An effective antiparasite vaccine platform is required to assess the effectiveness of novel vaccine candidates at high throughput. By exploiting the approach that has recently been used successfully to produce highly protective COVID mRNA vaccines, we anticipate a new wave of research to advance the use of mRNA vaccines to prevent parasitic infections in the near future. This article considers the characteristics that are required to develop a potent antiparasite vaccine and provides a conceptual foundation to promote the development of parasite mRNA-based vaccines. We review the recent advances and challenges encountered in developing antiparasite vaccines and evaluate the potential of developing mRNA vaccines against parasites, including those causing diseases such as malaria and schistosomiasis, against which vaccines are currently suboptimal or not yet available.

mRNA vaccines: The future of prevention of viral infections?

Messenger RNA (mRNA) vaccines against COVID-19 are the first authorized biological preparations developed using this platform. During the pandemic, their administration has been proven to be a life-saving intervention. Here, we review the main advantages of using mRNA vaccines, identify further technological challenges to be met during the development of the mRNA platform, and provide an update on the clinical progress on leading mRNA vaccine candidates against different viruses that include influenza viruses, human immunodeficiency virus 1, respiratory syncytial virus, Nipah virus, Zika virus, human cytomegalovirus, and Epstein-Barr virus. The prospects and challenges of manufacturing mRNA vaccines in low-income countries are also discussed. The ongoing interest and research in mRNA technology are likely to overcome some existing challenges for this technology (e.g., related to storage conditions and immunogenicity of some components of lipid nanoparticles) and enhance the portfolio of vaccines against diseases for which classical formulations are already authorized. It may also open novel pathways of protection against infections and their consequences for which no safe and efficient immunization methods are currently available.

The Combination of an mRNA Immunogen, a TLR7 Agonist and a PD1 Blocking Agent Enhances In-Vitro HIV T-Cell Immune Responses

The development of new strategies to achieve a functional cure for HIV remains a priority. We tested a novel HIV therapeutic vaccine using unmodified mRNA (TMEP-B) and mRNA modified by 1-methyl-3'-pseudouridylyl (TMEP-Bmod) expressing both a multiepitopic sequences from Gag, Pol, and Nef proteins, including different CD4 and CD8 T-cell epitopes functionally associated with HIV control in transfected monocyte-derived dendritic cells (MDDCs) obtained from HIV infected patients. In vitro assays were used to test the mRNAs alone and in combination with immunomodulator agents, such as the TLR-7 agonist Vesatolimod and the PD-1 antagonist Nivolumab to try to improve HIV-specific cellular immune responses. Combining the mRNAs with the immunomodulators enhanced HIV-specific T-cell responses, together with the secretion of IFNγ, IP10, MIP-1α, and MIP-1β, which are fundamental mediators of viral control. Our data suggest that the mRNA vaccine prototypes TMEP-B and TMEP-Bmod, when combined with Vesatolimod and/or Nivolumab, could achieve functional cure for patients with HIV.

Protein Transduction Domain-Mediated Delivery of Recombinant Proteins and In Vitro Transcribed mRNAs for Protein Replacement Therapy of Human Severe Genetic Mitochondrial Disorders: The Case of Sco2 Deficiency

Mitochondrial disorders represent a heterogeneous group of genetic disorders with variations in severity and clinical outcomes, mostly characterized by respiratory chain dysfunction and abnormal mitochondrial function. More specifically, mutations in the human SCO2 gene, encoding the mitochondrial inner membrane Sco2 cytochrome c oxidase (COX) assembly protein, have been implicated in the mitochondrial disorder fatal infantile cardioencephalomyopathy with COX deficiency. Since an effective treatment is still missing, a protein replacement therapy (PRT) was explored using protein transduction domain (PTD) technology. Therefore, the human recombinant full-length mitochondrial protein Sco2, fused to TAT peptide (a common PTD), was produced (fusion Sco2 protein) and successfully transduced into fibroblasts derived from a SCO2/COX-deficient patient. This PRT contributed to effective COX assembly and partial recovery of COX activity. In mice, radiolabeled fusion Sco2 protein was biodistributed in the peripheral tissues of mice and successfully delivered into their mitochondria. Complementary to that, an mRNA-based therapeutic approach has been more recently considered as an innovative treatment option. In particular, a patented, novel PTD-mediated IVT-mRNA delivery platform was developed and applied in recent research efforts. PTD-IVT-mRNA of full-length SCO2 was successfully transduced into the fibroblasts derived from a SCO2/COX-deficient patient, translated in host ribosomes into a nascent chain of human Sco2, imported into mitochondria, and processed to the mature protein. Consequently, the recovery of reduced COX activity was achieved, thus suggesting the potential of this mRNA-based technology for clinical translation as a PRT for metabolic/genetic disorders. In this review, such research efforts will be comprehensibly presented and discussed to elaborate their potential in clinical application and therapeutic usefulness.

Lipid Microparticles Show Similar Efficacy With Lipid Nanoparticles in Delivering mRNA and Preventing Cancer

PURPOSE

Messenger RNA (mRNA) has shown great promise for vaccine against both infectious diseases and cancer. However, mRNA is unstable and requires a delivery vehicle for efficient cellular uptake and degradation protection. So far, lipid nanoparticles (LNPs) represent the most advanced delivery platform for mRNA delivery. However, no published studies have compared lipid microparticles (LMPs) with lipid nanoparticles (LNPs) in delivering mRNA systematically, therefore, we compared the impact of particle size on delivery efficacy of mRNA vaccine and subsequent immune responses.

METHODS

Herein, we prepared 3 different size lipid particles, from nano-sized to micro-sized, and they loaded similar amounts of mRNA. These lipid particles were investigated both in vitro and in vivo, followed by evaluating the impact of particle size on inducing cellular and humoral immune responses.

RESULTS

In this study, all mRNA vaccines showed a robust immune response and lipid microparticles (LMPs) show similar efficacy with lipid nanoparticles (LNPs) in delivering mRNA and preventing cancer. In addition, immune adjuvants, either toll like receptors or active molecules from traditional Chinese medicine, can improve the efficacy of mRNA vaccines.

CONCLUSIONS

Considering the efficiency of delivery and endocytosis, besides lipid nanoparticles with size smaller than 150 nm, lipid microparticles (LMPs) also have the potential to be an alternative and promising delivery system for mRNA vaccines.

mRNA-Based Vaccines and Therapeutics for COVID-19 and Future Pandemics

An unheard mobilization of resources to find SARS-CoV-2 vaccines and therapies has been sparked by the COVID-19 pandemic. Two years ago, COVID-19's launch propelled mRNA-based technologies into the public eye. Knowledge gained from mRNA technology used to combat COVID-19 is assisting in the creation of treatments and vaccines to treat existing illnesses and may avert pandemics in the future. Exploiting the capacity of mRNA to create therapeutic proteins to impede or treat a variety of illnesses, including cancer, is the main goal of the quickly developing, highly multidisciplinary field of biomedicine. In this review, we explore the potential of mRNA as a vaccine and therapeutic using current research findings.

Enhancing the Effect of Nucleic Acid Vaccines in the Treatment of HPV-Related Cancers: An Overview of Delivery Systems

Prophylactic vaccines against human papillomavirus (HPV) have proven efficacy in those who have not been infected by the virus. However, they do not benefit patients with established tumors. Therefore, the development of therapeutic options for HPV-related malignancies is critical. Third-generation vaccines based on nucleic acids are fast and simple approaches to eliciting adaptive immune responses. However, techniques to boost immunogenicity, reduce degradation, and facilitate their capture by immune cells are frequently required. One option to overcome this constraint is to employ delivery systems that allow selective antigen absorption and help modulate the immune response. This review aimed to discuss the influence of these different systems on the response generated by nucleic acid vaccines. The results indicate that delivery systems based on lipids, polymers, and microorganisms such as yeasts can be used to ensure the stability and transport of nucleic acid vaccines to their respective protein synthesis compartments. Thus, in view of the limitations of nucleic acid-based vaccines, it is important to consider the type of delivery system to be used-due to its impact on the immune response and desired final effect.

DNA and mRNA Vaccines for Chronic Viral Infections and Cancer: Rationale, Mechanisms, and Progress

Interest in the capabilities of nucleic acid vaccines, (DNA and mRNA vaccines) for both prophylactic and therapeutic uses have greatly increased following the successful deployment of two mRNA and, on a more limited scale, one DNA vaccine for COVID-19. In addition to targeting other pathogens for prophylactic vaccines, efforts are also being made towards using them for therapies for chronic infections and cancer. An examination of past and current successes for such therapies using other technologies with an emphasis on the immunological mechanisms will be provided followed by an assessment of the relevant characteristics of DNA and mRNA vaccines to predict their utility for therapies for chronic viral infections and cancer. Efforts and progress for these targets will be described.

Polymeric Nanoparticles for Inhaled Vaccines

Many recent studies focus on the pulmonary delivery of vaccines as it is needle-free, safe, and effective. Inhaled vaccines enhance systemic and mucosal immunization but still faces many limitations that can be resolved using polymeric nanoparticles (PNPs). This review focuses on the use of properties of PNPs, specifically chitosan and PLGA to be used in the delivery of vaccines by inhalation. It also aims to highlight that PNPs have adjuvant properties by themselves that induce cellular and humeral immunogenicity. Further, different factors influence the behavior of PNP in vivo such as size, morphology, and charge are discussed. Finally, some of the primary challenges facing PNPs are reviewed including formulation instability, reproducibility, device-related factors, patient-related factors, and industrial-level scale-up. Herein, the most important variables of PNPs that shall be defined in any PNPs to be used for pulmonary delivery are defined. Further, this study focuses on the most popular polymers used for this purpose.

Design Strategies for and Stability of mRNA-Lipid Nanoparticle COVID-19 Vaccines

Messenger RNA (mRNA) vaccines have shown great preventive potential in response to the novel coronavirus (COVID-19) pandemic. The lipid nanoparticle (LNP), as a non-viral vector with good safety and potency factors, is applied to mRNA delivery in the clinic. Among the recently FDA-approved SARS-CoV-2 mRNA vaccines, lipid-based nanoparticles have been shown to be well-suited to antigen presentation and enhanced immune stimulation to elicit potent humoral and cellular immune responses. However, a design strategy for optimal mRNA-LNP vaccines has not been fully elaborated. In this review, we comprehensively and systematically discuss the research strategies for mRNA-LNP vaccines against COVID-19, including antigen and lipid carrier selection, vaccine preparation, quality control, and stability. Meanwhile, we also discuss the potential development directions for mRNA-LNP vaccines in the future. We also conduct an in-depth review of those technologies and scientific insights in regard to the mRNA-LNP field.

mRNA vaccines in the prevention and treatment of diseases

Messenger ribonucleic acid (mRNA) vaccines made their successful public debut in the effort against the COVID-19 outbreak starting in late 2019, although the history of mRNA vaccines can be traced back decades. This review provides an overview to discuss the historical course and present situation of mRNA vaccine development in addition to some basic concepts that underly mRNA vaccines. We discuss the general preparation and manufacturing of mRNA vaccines and also discuss the scientific advances in the in vivo delivery system and evaluate popular approaches (i.e., lipid nanoparticle and protamine) in detail. Next, we highlight the clinical value of mRNA vaccines as potent candidates for therapeutic treatment and discuss clinical progress in the treatment of cancer and coronavirus disease 2019. Data suggest that mRNA vaccines, with several prominent advantages, have achieved encouraging results and increasing attention due to tremendous potential in disease management. Finally, we suggest some potential directions worthy of further investigation and optimization. In addition to basic research, studies that help to facilitate storage and transportation will be indispensable for practical applications.

The Delivery of mRNA Vaccines for Therapeutics

mRNA vaccines have been revolutionary in combating the COVID-19 pandemic in the past two years. They have also become a versatile tool for the prevention of infectious diseases and treatment of cancers. For effective vaccination, mRNA formulation, delivery method and composition of the mRNA carrier play an important role. mRNA vaccines can be delivered using lipid nanoparticles, polymers, peptides or naked mRNA. The vaccine efficacy is influenced by the appropriate delivery materials, formulation methods and selection of a proper administration route. In addition, co-delivery of several mRNAs could also be beneficial and enhance immunity against various variants of an infectious pathogen or several pathogens altogether. Here, we review the recent progress in the delivery methods, modes of delivery and patentable mRNA vaccine technologies.

Identification of Novel Tumor Antigens and the Immune Landscapes of Bladder Cancer Patients for mRNA Vaccine Development

Background

mRNA vaccines are a novel technology that provide a potential strategy for cancer treatment. However, few studies exist that are focused on the application and development of mRNA vaccines in bladder cancer (BLCA). Therefore, this study filtered candidate antigens and specific mRNA-suitable populations in BLCA via comprehensive multi-omics analysis.

Methods

Clinical information, follow-up information, and gene expression profiles were obtained from the TCGA and GEO databases. Somatic mutation and DNA copy number variation of BLCA were visualized by cBioPortal. Significant survival genes were analyzed by GEPIA2. TIMER was used to evaluate the connection between candidate antigens and infiltration of antigen-presenting cells. Consensus clustering analysis was performed to identify immune subtypes using the ConsensusClusterPlus package. The Monocle package was used to visualize the immune landscapes of each BLCA patient. Weighted gene co-expression network analysis (WGCNA) was used to identify key genes for mRNA vaccines.

Results

AP2S1, P3H4, and RAC3 were identified as candidate tumor-specific antigens for BLCA. Three immune subtypes were classified based on immune-related gene expression profiles. Patients with the BCS2 subtype were characterized as immune “cold” and exhibited upregulation of immunogenic cell death modulators, whereas patients with BCS1 and BCS3 were immune “hot” and had upregulation of immune checkpoints. Interestingly, patients with the BCS2 subtype had a better prognosis than other subtypes. The immune landscapes of each patient were visualized and revealed the heterogeneity within the BCS1 subtype. Finally, 13 key immune genes were identified.

Conclusions

AP2S1, P3H4, and RAC3 were identified as candidate tumor-specific antigens, and patients with the BCS2 and BCS1A subtypes were identified as candidate populations for mRNA vaccines. In summary, this study provides novel insights and a theoretical basis for mRNA vaccine development in BLCA and other malignancies.

What Should We Do after the COVID-19 Vaccination? Vaccine-Associated Diseases and Precautionary Measures against Adverse Reactions

COVID-19 vaccines have been used to counteract the global COVID-19 pandemic. While these are effective, adverse reactions have been reported, such as injection-site pain, muscle ache, fever, palpitation, and chest discomfort. The release of inflammatory cytokines, such as interleukin (IL)-6 and IL-1β, is a potential mechanism for post-vaccine side-effects. Chest discomfort after the vaccination, including myocarditis and acute coronary syndrome, is a particularly serious adverse reaction. It is important to be familiar with the differential diagnoses of chest discomfort and organ-specific diseases associated with COVID-19 vaccines as the preparation for booster shots and vaccinations among children aged 5–11 years begins. High-intensity exercise, alcohol, tobacco smoking, and baths promote inflammatory cytokines, such as IL-6, which may exacerbate the adverse reactions after vaccination. Japanese data show that deaths during baths are the most common for several days after mRNA vaccination. Additionally, alcohol and tobacco smoking were identified as predictive factors of lower antibody titers after vaccination. In this review, we aimed to provide a few recommendations to prevent vaccine-associated disease.

Safety and Efficacy of Combined Intramuscular/Intranasal RAZI-COV PARS Vaccine Candidate Against SARS-CoV-2: A Preclinical Study in Several Animal Models

Several vaccine candidates for COVID-19 have been developed, and few vaccines received emergency approval with an acceptable level of efficacy and safety. We herein report the development of the first recombinant protein-based vaccine in Iran based on the recombinant SARS-CoV-2 spike protein in its monomeric (encompassing amino acid 1-674 for S1 and 685-1211 for S2 subunits) and trimer form (S-Trimer) formulated in the oil-in-water adjuvant system RAS-01 (Razi Adjuvant System-01). The safety and immunity of the candidate vaccine, referred to as RAZI-COV PARS, were evaluated in Syrian hamster, BALB/c mice, Pirbright guinea pig, and New Zeeland white (NZW) rabbit. All vaccinated animals received two intramuscular (IM) and one intranasal (IN) candidate vaccine at 3-week intervals (days 0, 21, and 51). The challenge study was performed intranasally with 5×106 pfu of SARS-CoV-2 35 days post-vaccination. None of the vaccinated mice, hamsters, guinea pigs, or rabbits showed any changes in general clinical observations; body weight and food intake, clinical indicators, hematology examination, blood chemistry, and pathological examination of vital organs. Safety of vaccine after the administration of single and repeated dose was also established. Three different doses of candidate vaccine stimulated remarkable titers of neutralizing antibodies, S1, Receptor-Binding Domain (RBD), and N-terminal domain (NTD) specific IgG antibodies as well as IgA antibodies compared to placebo and control groups (P<0.01). Middle and high doses of RAZI-COV PARS vaccine significantly induced a robust and quick immune response from the third-week post-immunization. Histopathological studies on vaccinated hamsters showed that the challenge with SARS-CoV-2 did not induce any modifications in the lungs. The protection of the hamster was documented by the absence of lung pathology, the decreased virus load in the lung, rapid clearance of the virus from the lung, and strong humoral and cellular immune response. These findings confirm the immunogenicity and efficacy of the RAZI-COV PARS vaccine. Of the three tested vaccine regimens, the middle dose of the vaccine showed the best protective immune parameters. This vaccine with heterologous prime-boost vaccination method can be a good candidate to control the viral infection and its spread by stimulating central and mucosal immunity.

mRNA-based therapeutics: powerful and versatile tools to combat diseases

The therapeutic use of messenger RNA (mRNA) has fueled great hope to combat a wide range of incurable diseases. Recent rapid advances in biotechnology and molecular medicine have enabled the production of almost any functional protein/peptide in the human body by introducing mRNA as a vaccine or therapeutic agent. This represents a rising precision medicine field with great promise for preventing and treating many intractable or genetic diseases. In addition, in vitro transcribed mRNA has achieved programmed production, which is more effective, faster in design and production, as well as more flexible and cost-effective than conventional approaches that may offer. Based on these extraordinary advantages, mRNA vaccines have the characteristics of the swiftest response to large-scale outbreaks of infectious diseases, such as the currently devastating pandemic COVID-19. It has always been the scientists’ desire to improve the stability, immunogenicity, translation efficiency, and delivery system to achieve efficient and safe delivery of mRNA. Excitingly, these scientific dreams have gradually been realized with the rapid, amazing achievements of molecular biology, RNA technology, vaccinology, and nanotechnology. In this review, we comprehensively describe mRNA-based therapeutics, including their principles, manufacture, application, effects, and shortcomings. We also highlight the importance of mRNA optimization and delivery systems in successful mRNA therapeutics and discuss the key challenges and opportunities in developing these tools into powerful and versatile tools to combat many genetic, infectious, cancer, and other refractory diseases.

Development of DNA Vaccine Candidate against SARS-CoV-2

Despite the existence of various types of vaccines and the involvement of the world’s leading pharmaceutical companies, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains the most challenging health threat in this century. Along with the increased transmissibility, new strains continue to emerge leading to the need for more vaccines that would elicit protectiveness and safety against the new strains of the virus. Nucleic acid vaccines seem to be the most effective approach in case of a sudden outbreak of infection or the emergence of a new strain as it requires less time than any conventional vaccine development. Hence, in the current study, a DNA vaccine encoding the trimeric prefusion-stabilized ectodomain (S1+S2) of SARS-CoV-2 S-protein was designed by introducing six additional prolines mutation, termed HexaPro. The three-dose regimen of designed DNA vaccine immunization in mice demonstrated the generation of protective antibodies.

Epigenomic alterations in cancer: mechanisms and therapeutic potential

The human cell requires ways to specify its transcriptome without altering the essential sequence of DNA; this is achieved through mechanisms which govern the epigenetic state of DNA and epitranscriptomic state of RNA. These alterations can be found as modified histone proteins, cytosine DNA methylation, non-coding RNAs, and mRNA modifications, such as N6-methyladenosine (m6A). The different aspects of epigenomic and epitranscriptomic modifications require protein complexes to write, read, and erase these chemical alterations. Reflecting these important roles, many of these reader/writer/eraser proteins are either frequently mutated or differentially expressed in cancer. The disruption of epigenetic regulation in the cell can both contribute to cancer initiation and progression, and increase the likelihood of developing resistance to chemotherapies. Development of therapeutics to target proteins involved in epigenomic/epitranscriptomic modifications has been intensive, but further refinement is necessary to achieve ideal treatment outcomes without too many off-target effects for cancer patients. Therefore, further integration of clinical outcomes combined with large-scale genomic analyses is imperative for furthering understanding of epigenomic mechanisms in cancer.

Multimeric RNAs for efficient RNA-based therapeutics and vaccines

There has been a growing interest in RNA therapeutics globally, and much progress has been made in this area, which has been further accelerated by the clinical applications of RNA-based vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Following these successful clinical trials, various technologies have been developed to improve the efficacy of RNA-based drugs. Multimerization of RNA therapeutics is one of the most attractive approaches to ensure high stability, high efficacy, and prolonged action of RNA-based drugs. In this review, we offer an overview of the representative approaches for generating repetitive functional RNAs by chemical conjugation, structural self-assembly, enzymatic elongation, and self-amplification. The therapeutic and vaccine applications of engineered multimeric RNAs in various diseases have also been summarized. By outlining the current status of multimeric RNAs, the potential of multimeric RNA as a promising treatment strategy is highlighted.

Messenger RNA vaccines for cancer immunotherapy: progress promotes promise

The COVID-19 pandemic has elevated mRNA vaccines to global recognition due to their unprecedented success rate in protecting against a deadly virus. This international success is underscored by the remarkable versatility, favorable immunogenicity, and overall safety of the mRNA platform in diverse populations. Although mRNA vaccines have been studied in preclinical models and patients with cancer for almost three decades, development has been slow. The recent technological advances responsible for the COVID-19 vaccines have potential implications for successfully adapting this vaccine platform for cancer therapeutics. Here we discuss the lessons learned along with the chemical, biologic, and immunologic adaptations needed to optimize mRNA technology to successfully treat cancers.