Modified mRNA Vaccines Protect against Zika Virus Infection

Pathogenesis and clinical management of arboviral diseases

Arboviral diseases are viral infections transmitted to humans through the bites of arthropods, such as mosquitoes, often causing a variety of pathologies associated with high levels of morbidity and mortality. Over the past decades, these infections have proven to be a significant challenge to health systems worldwide, particularly following the considerable geographic expansion of the dengue virus (DENV) and its most recent outbreak in Latin America as well as the difficult-to-control outbreaks of yellow fever virus (YFV), chikungunya virus (CHIKV), and Zika virus (ZIKV), leaving behind a substantial portion of the population with complications related to these infections. Currently, the world is experiencing a period of intense globalization, which, combined with global warming, directly contributes to wider dissemination of arbovirus vectors across the globe. Consequently, all continents remain on high alert for potential new outbreaks. Thus, this review aims to provide a comprehensive understanding of the pathogenesis of the four main arboviruses today (DENV, ZIKV, YFV, and CHIKV) discussing their viral characteristics, immune responses, and mechanisms of viral evasion, as well as important clinical aspects for patient management. This includes associated symptoms, laboratory tests, treatments, existing or developing vaccines and the main associated complications, thus integrating a broad historical, scientific and clinical approach.

Research progress of mosquito-borne virus mRNA vaccines

In recent years, mRNA vaccines have emerged as a leading technology for preventing infectious diseases due to their rapid development and high immunogenicity. These vaccines encode viral antigens, which are translated into antigenic proteins within host cells, inducing both humoral and cellular immune responses. This review systematically examines the progress in mRNA vaccine research for major mosquito-borne viruses, including dengue virus, Zika virus, Japanese encephalitis virus, Chikungunya virus, yellow fever virus, Rift Valley fever virus, and Venezuelan equine encephalitis virus. Enhancements in mRNA vaccine design, such as improvements to the 5' cap structure, 5'UTR, open reading frame, 3'UTR, and polyadenylation tail, have significantly increased mRNA stability and translation efficiency. Additionally, the use of lipid nanoparticles and polymer nanoparticles has greatly improved the delivery efficiency of mRNA vaccines. Currently, mRNA vaccines against mosquito-borne viruses are under development and clinical trials, showing promising protective effects. Future research should continue to optimize vaccine design and delivery systems to achieve broad-spectrum and long-lasting protection against various mosquito-borne virus infections.

A review of advances in in vitro RNA preparation by ssRNAP

In vitro transcription (IVT) based on single-subunit RNA polymerase (ssRNAP) has enhanced the widespread application of RNA drugs in the biomedical field, showcasing unprecedented potential for disease prevention and treatment. While the classical enzyme T7 RNA polymerase (T7 RNAP) has driven significant progress in RNA production, several challenges persist. These challenges include the selectivity of the initiation nucleotide, low incorporation efficiency of modified nucleotides, limited processivity on certain templates, heterogeneity at the 3' end of RNA products, and high level of double-stranded RNA (dsRNA) byproducts. No review has systematically addressed the efforts to overcome these challenges. To fill this gap, we reviewed recent advances in engineering T7 RNAP variants and the discovery of novel ssRNAPs aimed at addressing the shortcomings of T7 RNAP. We also discussed the underlying mechanisms of ssRNAP-mediated byproduct formation, strategies to mitigate dsRNA production using modified nucleotides, and for the first time to sorted out the application of artificial intelligence in IVT. Overall, this review summarizes the advances in RNA synthesis via IVT and provides potential strategies for improving RNA products. We believe that ssRNAPs with more excellent performance will be on the stage of RNA synthesis in the near future to meet the growing demands of both scientific research and pharmaceutical industry.

Avian influenza mRNA vaccine encoding hemagglutinin provides complete protection against divergent H5N1 viruses in specific-pathogen-free chickens

BACKGROUND

The rapid mutation of avian influenza virus (AIV) poses a significant threat to both the poultry industry and public health. Herein, we have successfully developed an mRNA-LNPs candidate vaccine for H5 subtype highly pathogenic avian influenza and evaluated its immunogenicity and protective efficacy.

RESULTS

In experiments on BALB/c mice, the vaccine candidate elicited strong humoral and a certain cellular immune responses and protected mice from the heterologous AIV challenge. Antibody and splenocyte passive transfer assays in mice suggested that antibodies played a crucial role in providing protection. Experiments involving SPF chickens have revealed that two doses of the 5 µg vaccine candidate in this study provided 100% complete protection against homologous strains, but only 50% complete protection against heterologous strains. Even immunization with two doses of the 15 µg vaccine candidate resulted in 90% complete protection against heterologous strains. To enhance the immune efficacy of the candidate vaccine, we designed 6 sequences with different secondary structures and screened out the candidate sequence with the highest expression (SY2-HA mRNA). Experiments on SPF chickens showed that two doses of 5 µg SY2-HA mRNA-LNP vaccine provided 100% complete protection against homologous and heterologous H5N1 AIV strains. Immunization tests with the SY2-HA mRNA-LNP vaccine were repeated in the SPF chicken model, inducing antibody production levels that are consistent with previous tests and providing 100% complete protection against both homologous and heterologous strains of the virus, indicating that the vaccine has a stable immune efficacy.

CONCLUSIONS

The vaccine developed in this study provides complete protection against divergent H5N1 AIV strains in chickens, offering a promising approach for the future development of mRNA vaccines against multivalent avian influenza subtypes.

mRNA-LM: full-length integrated SLM for mRNA analysis

The success of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) messenger RNA (mRNA) vaccine has led to increased interest in the design and use of mRNA for vaccines and therapeutics. Still, selecting the most appropriate mRNA sequence for a protein remains a challenge. Several recent studies have shown that the specific mRNA sequence can have a significant impact on the translation efficiency, half-life, degradation rates, and other issues that play a major role in determining vaccine efficiency. To enable the selection of the most appropriate sequence, we developed mRNA-LM, an integrated small language model for modeling the entire mRNA sequence. mRNA-LM uses the contrastive language-image pretraining integration technology to combine three separate language models for the different mRNA segments. We trained mRNA-LM on millions of diverse mRNA sequences from several different species. The unsupervised model was able to learn meaningful biology related to evolution and host-pathogen interactions. Fine-tuning of mRNA-LM allowed us to use it in several mRNA property prediction tasks. As we show, using the full-length integrated model led to accurate predictions, improving on prior methods proposed for this task.

Delivery of FGF18 using mRNA-LNP protects the cartilage against degeneration via alleviating chondrocyte senescence

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease with an immense unmet medical need. FGF18 protein is a potential regenerative factor for cartilage repair. However, traditional protein delivery methods have limited efficacy due to the short lifetime and shallow infiltration.

RESULTS

In this work, we discovered that lipid nanoparticle (LNP) can infiltrate and deliver FGF18 mRNA deeper in the cartilage than proteins. After mRNA UTR optimization and chemical modification, the expression of FGF18 can last up to 6 days in the cartilage. Furthermore, delivering FGF18 mRNA activates FOXO3a-autophagy pathway, which protects against chondrocyte degeneration and senescence. Local intra-articular injection of FGF18 mRNA-LNP significantly alleviates OA symptoms in DMM and senile OA models. Sustained expression and accessibility of FGF18-mRNA to deeper chondrocytes makes LNP-mRNA more effective than FGF18 recombinant protein.

CONCLUSIONS

In summary, this study presents a novel approach superior to recombinant protein alone and holds promise as a new therapeutic strategy for OA.

Enhanced mRNA delivery via incorporating hydrophobic amines into lipid nanoparticles

Lipid nanoparticles (LNPs) have shown promising performance in mRNA delivery. Nevertheless, a thorough understanding of the relationship between mRNA delivery efficacy and the structure of LNPs remains imperative. In this study, we systematically investigated the effects of additional hydrophobic amines on the physicochemical properties of mRNA LNPs and their delivery efficacy. The results indicated that this influence depended on the chemical structure of the additional amines and the structure of the lipid carriers. The appropriate addition of the hydrophobic amine 2C8 to lipid carriers with structural 2C8 or 2C6 tails significantly increased their mRNA delivery efficiency. In contrast, the addition of hydrophobic amine C18 to LNPs resulted in a decrease in mRNA delivery efficiency, while the addition of hydrophobic amines 2C6 and C8, as well as alkanes C12' and C16', had relatively little effect on mRNA delivery. Further investigations demonstrated that the appropriate addition of 2C8 could reduce LNP size, moderate internal hydrophobicity and LNP stability, facilitate mRNA release, enhance cellular uptake, and improve intracellular transportation of LNPs, thereby achieving superior mRNA delivery efficiency. These findings highlight the important role of additional hydrophobic amines in mRNA delivery with LNPs and provide valuable insights for the advancement of mRNA delivery carriers.

An mRNA-Based Respiratory Syncytial Virus Vaccine Elicits Strong Neutralizing Antibody Responses and Protects Rodents Without Vaccine-Associated Enhanced Respiratory Disease

BACKGROUND

Respiratory syncytial virus (RSV) causes the most common type of severe lower respiratory tract infection worldwide, and the fusion (F) protein is a target for neutralizing antibodies and vaccine development. This study aimed to investigate the immunogenicity and efficacy of an mRNA-based RSV vaccine with an F protein sequence.

METHODS

We designed an mRNA construct encoding a modified RSV F protein, which was further developed into an LNP-encapsulated mRNA vaccine (LVRNA007). LVRNA007 was administered to mice and cotton rats, followed by immunogenicity analysis and viral challenge studies. Protection of rodents from the viral infection was evaluated based on the presence of the virus in the lung and pathological examination of respiratory tissues.

RESULTS

LVRNA007 induced robust humoral and cellular immune responses in both mice and cotton rats, with neutralization antibody levels in the immunized animals maintained at high levels for over one year. Vaccination of LVRNA007 also protected the rodents from RSV challenge, judged by the much decreased virus titer and the pathological score in the lung tissue. In addition, no vaccine-enhanced disease (VED) phenomenon was observed with LVRNA007 vaccination.

CONCLUSIONS

Based on the preclinical immunogenicity and efficacy data, LVRNA007 could be a potential promising vaccine for prophylaxis of RSV infection.

Efficient and safe in vivo treatment of primary hyperoxaluria type 1 via LNP-CRISPR-Cas9-mediated glycolate oxidase disruption

Primary hyperoxaluria type 1 (PH1) is a severe genetic metabolic disorder caused by mutations in the AGXT gene, leading to defects in enzymes crucial for glyoxylate metabolism. PH1 is characterized by severe, potentially life-threatening manifestations due to excessive oxalate accumulation, which leads to calcium oxalate crystal deposits in the kidneys and, ultimately, renal failure and systemic oxalosis. Existing substrate reduction therapies, such as inhibition of liver-specific glycolate oxidase (GO) encoded by HAO1 using siRNA or CRISPR-Cas9 delivered by adeno-associated virus, either require repeated dosing or have raised safety concerns. To address these limitations, our study employed lipid nanoparticles (LNPs) for CRISPR-Cas9 delivery to rapidly generate a PH1 mouse model and validate the therapeutic efficacy of LNP-CRISPR-Cas9 targeting the Hao1 gene. The LNP-CRISPR-Cas9 system exhibited efficient editing of the Hao1 gene, significantly reducing GO expression and lowering urinary oxalate levels in treated PH1 mice. Notably, these effects persisted for 12 months with no significant off-target effects, liver-induced toxicity, or substantial immune responses, highlighting the approach's safety and specificity. Furthermore, the developed humanized mouse model validated the efficacy of our therapeutic strategy. These findings support LNP-CRISPR-Cas9 targeting HAO1 as a promising and safer alternative for PH1 treatment with a single administration.

Development of nucleic acid-based vaccines against dengue and other mosquito-borne flaviviruses: the past, present, and future

Due to their widespread geographic distribution and frequent outbreaks, mosquito-borne flaviviruses, such as DENV (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV), yellow fever virus (YFV), and West Nile virus (WNV), are considered significant global public health threats and contribute to dramatic socioeconomic imbalances worldwide. The global prevalence of these viruses is largely driven by extensive international travels and ecological disruptions that create favorable conditions for the breeding of Aedes and Culex species, the mosquito vectors responsible for the spread of these pathogens. Currently, vaccines are available for only DENV, YFV, and JEV, but these face several challenges, including safety concerns, lengthy production processes, and logistical difficulties in distribution, especially in resource-limited regions, highlighting the urgent need for innovative vaccine approaches. Nucleic acid-based platforms, including DNA and mRNA vaccines, have emerged as promising alternatives due to their ability to elicit strong immune responses, facilitate rapid development, and support scalable manufacturing. This review provides a comprehensive update on the progress of DNA and mRNA vaccine development against mosquito-borne flaviviruses, detailing early efforts and current strategies that have produced candidates with remarkable protective efficacy and strong immunogenicity in preclinical models. Furthermore, we explore future directions for advancing nucleic acid vaccine candidates, which hold transformative potential for enhancing global public health.

Programmable Macrophage Vesicle Based Bionic Self-Adjuvanting Vaccine for Immunization against Monkeypox Virus

The emergence of monkeypox has become a global health threat after the COVID-19 pandemic. Due to the lack of available specifically treatment against MPV, developing an available vaccine is thus the most prospective and urgent strategy. Herein, a programmable macrophage vesicle based bionic self-adjuvanting vaccine (AM@AEvs-PB) is first developed for defending against monkeypox virus (MPV). Based on MPV-related antigen-stimulated macrophage-derived vesicles, the nanovaccine is constructed by loading the mature virion (MV)-related intracellular protein (A29L/M1R) and simultaneously modifying with the enveloped virion (EV) antigen (B6R), enabling them to effectively promote antigen presentation and enhance adaptive immune through self-adjuvant strategy. Owing to the synergistic properties of bionic vaccine coloaded MV and EV protein in defensing MPV, the activation ratio of antigen-presenting cells is nearly four times than that of single antigen in the same dose, resulting in stronger immunity in host. Notably, intramuscular injection uptake of AM@AEvs-PB demonstrated vigorous immune-protective effects in the mouse challenge attempt, offering a promising strategy for pre-clinical monkeypox vaccine development.

Immunogenicity and protection of a triple repeat domain III mRNA vaccine against Zika virus

Zika virus (ZIKV) infection is primarily transmitted by mosquitoes and often asymptomatic in most individuals. Infection during pregnancy can lead to severe birth defects such as congenital microcephaly, and currently, there is no approved vaccine for ZIKV. Several studies are investigating the development of ZIKV vaccine using DNA and RNA as well as recombinant protein technologies; however, the outcomes thus far have not been consistently noteworthy. In this study, we designed an mRNA vaccine for ZIKV and evaluated its immunogenicity using a mouse model. Our vaccine, termed 3xEIII, encodes a triple repeat of domain III from the ZIKV E protein. We effectively encapsulated the mRNA within lipid nanoparticles (LNPs), administered 3xEIII to mice via two intramuscular injections, and assessed the induced humoral and cellular immune responses. Specifically, the vaccine elicited neutralizing antibodies that effectively eliminated ZIKV from the organs of challenged mice. Notably, 3xEIII conferred both protective effects and long-term immunity. In subsequent challenges conducted 40 weeks after boosting, immunized mice experienced temporary weight loss but showed significantly reduced viral titers in target organs by the 9th day post-infection. Conclusively from these findings, 3xEIII stands out as a promising noteworthy mRNA vaccine candidate for Zika virus.

Adjusting susceptibilities of C57BL/6 mice to orthoflaviviruses for evaluation of antiviral drugs by altering the levels of interferon alpha/beta receptor function

The purpose of this study was to optimize the infectivity of four different orthoflaviviruses in mice for evaluating antiviral drugs by using wild-type mice with intact interferon responses, type 1 interferon alpha/beta receptor knockout mice, or by injecting wild type C57BL/6 mice with varying doses of anti-type 1 interferon receptor antibody (MAR1-5A3) to optimize the infectivity and lethality. West Nile virus productively infected wild-type C57BL/6 mice to cause lethality, whereas Usutu virus required a complete absence of type 1 interferon receptor function. Deer tick virus (lineage 2 Powassan virus) and Japanese encephalitis viruses required a dampening of type 1 interferon responses by adjusting the doses of MAR1-5A3 antibody injections. Challenge dose-responsive mortality, weight loss, and viral titers of these two viruses were observed if the type 1 interferon responses were dampened with MAR1-5A3. Conversely, without MAR1-5A3 injections, these disease phenotypes were not viral challenge dose-responsive. From these different interferon-responsive models, the appropriate lethality was identified to determine that 7-deaza-2'-C-methyladenosine has high efficacy for West Nile and Usutu viruses, and low efficacy for deer tick and Japanese encephalitis viruses.

MHCI trafficking signal-based mRNA vaccines strengthening immune protection against RNA viruses

The major histocompatibility complex class I (MHCI) trafficking signal (MITD) plays a pivotal role in enhancing the efficacy of mRNA vaccines. However, there was a lack of research investigating its efficacy in enhancing immune responses to RNA virus infections. Here, we have developed an innovative strategy for the formulation of mRNA vaccines. This approach involved the integration of MITD into the mRNA sequence encoding the virus antigen. Mechanistically, MITD-based mRNA vaccines can strengthen immune protection by mimicking the dynamic trafficking properties of MHCI molecule and thus expand the memory specific B and T cells. The model MITD-based mRNA vaccines encoding binding receptor-binding domain (RBD) of SARS-CoV-2 were indeed found to achieve protective duration, optimal storage stability, broad efficacy, and high safety.

Development of mRNA rabies vaccines

Rabies, primarily transmitted to humans by dogs (accounting for 99% of cases). Once rabies occurs, its mortality rate is approximately 100%. Post-exposure prophylaxis (PEP) is critical for preventing the onset of rabies after exposure to rabid animals, and vaccination is a pivotal element of PEP. However, high costs and complex immunization protocols have led to poor adherence to rabies vaccinations. Consequently, there is an urgent need to develop new rabies vaccines that are safe, highly immunogenic, and cost-effective to improve compliance and effectively prevent rabies. In recent years, mRNA vaccines have made significant progress in the structural modification and optimization of delivery systems. Various mRNA vaccines are currently undergoing clinical trials, positioning them as viable alternatives to the traditional rabies vaccines. In this article, we discuss a novel mRNA rabies vaccine currently undergoing clinical and preclinical testing, and evaluate its potential to replace existing vaccines.

Comparison of Three Chimeric Zika Vaccine Prototypes Developed on the Genetic Background of the Clinically Proven Live-Attenuated Japanese Encephalitis Vaccine SA14-14-2

Zika virus (ZIKV) is a medically important mosquito-borne orthoflavivirus, but no vaccines are currently available to prevent ZIKV-associated disease. In this study, we compared three recombinant chimeric viruses developed as candidate vaccine prototypes (rJEV/ZIKVMR-766, rJEV/ZIKVP6-740, and rJEV/ZIKVPRVABC-59), in which the two neutralizing antibody-inducing prM and E genes from each of three genetically distinct ZIKV strains were used to replace the corresponding genes of the clinically proven live-attenuated Japanese encephalitis virus vaccine SA14-14-2 (rJEV). In WHO-certified Vero cells (a cell line suitable for vaccine production), rJEV/ZIKVP6-740 exhibited the slowest viral growth, formed the smallest plaques, and displayed a unique protein expression profile with the highest ratio of prM to cleaved M when compared to the other two chimeric viruses, rJEV/ZIKVMR-766 and rJEV/ZIKVPRVABC-59, as well as their vector, rJEV. In IFNAR-/- mice, an animal model of ZIKV infection, subcutaneous inoculation of rJEV/ZIKVP6-740 caused a low-level localized infection limited to the spleen, with no clinical signs of infection, weight loss, or mortality; in contrast, the other two chimeric viruses and their vector caused high-level systemic infections involving multiple organs, consistently leading to clear clinical signs of infection, rapid weight loss, and 100% mortality. Subsequently, subcutaneous immunization with rJEV/ZIKVP6-740 proved highly effective, offering complete protection against a lethal intramuscular ZIKV challenge 28 days after a single-dose immunization. This protection was specific to ZIKV prM/E and likely mediated by neutralizing antibodies targeting ZIKV prM/E. Therefore, our data indicate that the chimeric virus rJEV/ZIKVP6-740 is a highly promising vaccine prototype for developing a safe and effective vaccine for inducing neutralizing antibody-mediated protective immunity against ZIKV.

Animal Models, Therapeutics, and Vaccine Approaches to Emerging and Re-Emerging Flaviviruses

Flaviviruses are arthropod-borne viruses primarily transmitted through the mosquito Aedes aegypti or Culex genus of mosquitos. These viruses are predominantly found in tropical and subtropical regions of the world with their geographical spread predicted to increase as global temperatures continue to rise. These viruses cause a variety of diseases in humans with the most prevalent being caused by dengue, resulting in hemorrhagic fever and associated sequala. Current approaches for therapeutic control of flavivirus infections are limited, and despite recent advances, there are no approved drugs. Vaccines, available for a few circulating flaviviruses, still have limited potential for controlling contemporary and future outbreaks. Mouse models provide us with a valuable tool to test the effectiveness of drugs and vaccines, yet for many flaviviruses, well-established mouse models are lacking. In this review, we highlight the current state of flavivirus vaccines and therapeutics, as well as our current understanding of mouse models for various flaviviruses.

Lipid nanoparticles as adjuvant of norovirus VLP vaccine augment cellular and humoral immune responses in a TLR9- and type I IFN-dependent pathway

Norovirus (NoV) virus-like particles (VLPs) adjuvanted with aluminum hydroxide (Alum) are common vaccine candidates in clinical studies. Alum adjuvants usually inefficiently assist recombinant proteins to induce cellular immune responses. Thus, novel adjuvants are required to develop NoV vaccines that could induce both efficient humoral and robust cellular immune responses. Lipid nanoparticles (LNPs) are well-known mRNA delivery vehicles. Increasing evidence suggests that LNPs may have intrinsic adjuvant activity and can be used as adjuvants for recombinant protein vaccines; however, the underlying mechanism remains poorly understood. In this study, we compared the adjuvant effect of LNPs and Alum for a bivalent GI.1/GII.4 NoV VLP vaccine. Compared with Alum, LNP-adjuvanted vaccines induced earlier production of binding, blocking, and neutralizing antibodies and promoted a more balanced IgG2a/IgG1 ratio. It is crucial that LNP-adjuvanted vaccines induced stronger Th1-type cytokine-producing CD4+ T cell and CD8+ T cell responses than Alum. The adjuvant activity of LNPs depended on the ionizable lipid components. Mechanistically, LNPs activated innate immune responses in a type I IFN-dependent manner and were partially dependent on Toll-like receptor (TLR) 9, thus affecting the adaptive immune responses of the vaccine. This conclusion was supported by RNA-seq analysis and in vitro cell experiments and by the deeply blunted T cell responses in IFNαR1-/- mice immunized with LNP-adjuvanted vaccines. This study not only identified LNPs as a high quality adjuvant for NoV VLP vaccines, but also clarified the underlying mechanism of LNPs as a potent immunostimulatory component for improving protein subunit vaccines.IMPORTANCEWith the rapid development of mRNA vaccines, recurrent studies show that lipid nanoparticles (LNPs) have adjuvant activity. However, the mechanism of its adjuvant effect in protein vaccines remains unknown. In this study, we found that the LNP-adjuvanted norovirus bivalent virus-like particle vaccines led to durable antibody responses as well as Th1-type cytokine-producing CD4+ T cell and CD8+ T cell responses, which exceeded the efficiency of the conventional adjuvant aluminum hydroxide. Mechanistically, LNPs activated innate immune responses in a type I IFN-dependent manner and were partially dependent on Toll-like receptor 9, thus affecting the adaptive immune responses of the vaccine. This work unveils that LNPs as a potent immunostimulatory component may be ideal for generating CD8+ T cell and B cell responses for recombinant protein vaccines.

Comprehensive analysis of lipid nanoparticle formulation and preparation for RNA delivery

Nucleic acid-based therapeutics are a common approach that is increasingly popular for a wide spectrum of diseases. Lipid nanoparticles (LNPs) are promising delivery carriers that provide RNA stability, with strong transfection efficiency, favorable and tailorable pharmacokinetics, limited toxicity, and established translatability. In this review article, we describe the lipid-based delivery systems, focusing on lipid nanoparticles, the need of their use, provide a comprehensive analysis of each component, and highlight the advantages and disadvantages of the existing manufacturing processes. We further summarize the ongoing and completed clinical trials utilizing LNPs, indicating important aspects/questions worth of investigation, and analyze the future perspectives of this significant and promising therapeutic approach.

Paratransgenic quantum vaccinology

Tick vaccines are an environmentally friendly intervention for the prevention and control of tick-borne diseases affecting humans and animals worldwide. From our perspective, the challenges in tick vaccinology have encouraged the implementation of new interventions. In this opinion article we propose paratransgenic quantum vaccinology as a new approach that integrates platform trends in biotechnology, such as omics datasets combined with big data analytics, machine learning, and paratransgenesis with a systems biology perspective. This innovative approach allows the identification of protective epitopes in tick- and/or pathogen-derived proteins for the design of chimeric vaccine candidate antigens which can be produced by commensal/symbiotic microorganisms eliciting a protective response in the host.

A Narrative Review on the Pandemic Zoonotic RNA Virus Infections Occurred During the Last 25 Years

BACKGROUND

Pandemic zoonotic RNA virus infections have continued to threaten humans and animals worldwide. The objective of this review was to highlight the epidemiology and socioeconomic impacts of pandemic zoonotic RNA virus infections that occurred between 1997 and 2021.

METHODS

Literature search was done from Web of Science, PubMed, Google Scholar and Scopus databases, cumulative case fatalities of individual viral infection calculated, and geographic coverage of the pandemics were shown by maps.

RESULTS

Seven major pandemic zoonotic RNA virus infections occurred from 1997 to 2021 and were presented in three groups: The first group consists of highly pathogenic avian influenza (HPAI-H5N1) and swine-origin influenza (H1N1) viruses with cumulative fatality rates of 53.5% and 0.5% in humans, respectively. Moreover, HPAI-H5N1 infection caused 90-100% death in poultry and economic losses of >$10 billion worldwide. Similarly, H1N1 caused a serious infection in swine and economic losses of 0.5-1.5% of the Gross Domestic Product (GDP) of the affected countries. The second group consists of severe acute respiratory syndrome-associated coronavirus infection (SARS-CoV), Middle East Respiratory Syndrome (MERS-CoV) and Coronavirus disease 2019 (COVID-19) with case fatalities of 9.6%, 34.3% and 2.0%, respectively in humans; but this group only caused mild infections in animals. The third group consists of Ebola and Zika virus infections with case fatalities of 39.5% and 0.02%, respectively in humans but causing only mild infections in animals.

CONCLUSION

Similar infections are expected in the near future, and hence strict implementation of conventional biosecurity-based measures and development of efficacious vaccines would help minimize the impacts of the next pandemic infection.

Bioinformatics analysis to design a multi-epitope mRNA vaccine against S. agalactiae exploiting pathogenic proteins

Antibiotic resistance in bacterial pathogen infections is a growing global issue that occurs due to their adaptation to changing environmental conditions. Therefore, producing an efficient vaccine as an alternative approach can improve the immune system, eradicate related pathogens, and overcome this growing problem. Streptococcus agalactiae belongs to group B Streptococcus (GBS). Colonization of GBS during pregnancy is a significant risk factor for infants and young children. S. agalactiae infected population exhibits resistance to beta-lactams, including penicillin and the second-line antibiotics erythromycin and clindamycin. On the other hand, there are currently no commercial vaccines against this pathogen. Vaccination of pregnant women is a highly effective method to protect newborns and infants from S. agalactiae infection, and it has been identified as an urgent demand by the World Health Organization. This study employed various immunoinformatic tools to develop an effective vaccine that could trigger both humoral and cell-mediated immunity and prevent disease. For this purpose, three conserved antigenic proteins of the main pathogenic strains of S. agalactiae were utilized to predict CTL, HTL, and B-cell epitopes for producing an mRNA vaccine against different strains of S. agalactiae. The selected epitopes were fused using proper linkers. The Resuscitation promoting factor E (RpfE) sequence was incorporated in the designed vaccine construct as an adjuvant to boost its immune response. Different physicochemical characteristics of the final designed vaccine, modeling of the three-dimensional structure, molecular docking, molecular dynamics simulation, and immunological response simulation were screened following vaccine administration in an in vivo model. Computational immune simulation data identified that IgG1, IgM, INF γ, IL-2, T helper, and B-cell populations increased significantly after vaccination. These findings suggested that the vaccine candidate may provide good protection against S. agalactiae infection. However, experimental and animal model studies are required for additional validation and implementation in human vaccination programs.

Prophylactic and therapeutic vaccine development: advancements and challenges

Biomedical research is fundamental in developing preventive and therapeutic vaccines, serving as a cornerstone of global public health. This review explores the key concepts, methodologies, tools, and challenges in the vaccine development landscape, focusing on transitioning from basic biomedical sciences to clinical applications. Foundational disciplines such as virology, immunology, and molecular biology lay the groundwork for vaccine creation, while recent innovations like messenger RNA (mRNA) technology and reverse vaccinology have transformed the field. Additionally, it highlights the role of pharmaceutical advancements in translating lab discoveries into clinical solutions. Techniques like CRISPR-Cas9, genome sequencing, monoclonal antibodies, and computational modeling have significantly enhanced vaccine precision and efficacy, expediting the development of vaccines against infectious diseases. The review also discusses challenges that continue to hinder progress, including stringent regulatory pathways, vaccine hesitancy, and the rapid emergence of new pathogens. These obstacles underscore the need for interdisciplinary collaboration and the adoption of innovative strategies. Integrating personalized medicine, nanotechnology, and artificial intelligence is expected to revolutionize vaccine science further. By embracing these advancements, biomedical research has the potential to overcome existing challenges and usher in a new era of therapeutic and prophylactic vaccines, ultimately improving global health outcomes. This review emphasizes the critical role of vaccines in combating current and future health threats, advocating for continued investment in biomedical science and technology.

An engineered Japanese encephalitis virus mRNA-lipid nanoparticle immunization induces protective immunity in mice

Introduction

Japanese encephalitis virus (JEV) and Zika virus (ZIKV) pose a severe threat to human health. Our previous research results, as well as those of other research groups, indicated that antibodies (Abs) induced by JEV infection or JEV vaccine vaccination could enhance ZIKV infection in vitro and exacerbate the mortality of ZIKV-infected mice, vice versa, which is known as antibody-dependent enhancement (ADE). Although studies on other flaviviruses revealed that altering the amino acid residues located in the fusion loop (FL) of envelope (E) protein can reduce the level of flavivirus-cross-reactive Abs, thereby abating the ADE of heterologous flavivirus infection, it is unclear whether this strategy is equally applicable to JEV.

Methods

In this study, we constructed recombinant adenoviruses and nucleotide-modified mRNA-lipid nanoparticle (LNP) encoding JEV wild-type E protein or E protein mutant (designated as Ad5-JEV-EWT and Ad5-JEV-Emut; JEV-EWT mRNA-LNP, and JEV-Emut mRNA-LNP). We evaluated the immunogenicity of these vaccine candidates in mice and the capacity of vaccine-immune mouse sera to neutralize JEV infection or mediate ADE of ZIKV infection in vitro and in vivo.

Results

Ad5-JEV-Emut or JEV-Emut mRNA-LNP immunization induced ZIKV-cross-reactive Ab response which is dramatically lower than that induced by Ad5-JEV-EWT and JEV-EWT mRNA-LNP, respectively. The levels of JEV-neutralizing Abs induced by Ad5-JEV-Emut or JEV-Emut mRNA-LNP are comparable to that induced by Ad5-JEV-EWT and JEV-EWT mRNA-LNP, respectively. The ability of Abs induced by Ad5-JEV-Emut to enhance ZIKV infection in vitro is attenuated as compared with that induced by Ad5-JEV-EWT. Moreover, JEV-Emut mRNA-LNP immunization elicited potent T cell response similar to JEV-EWT mRNA-LNP in mice. Mice immunized with each mRNA-LNP exhibited lower level of serum viral load than the mock-immunized mice post JEV challenge. Mice receiving JEV-EWT mRNA-LNP-immune mouse sera exhibited ADE post ZIKV challenge whereas passively transferred JEV-Emut mRNA-LNP-immune mouse sera did not lead to obvious ADE of ZIKV infection in recipient mice. Most importantly, maternally acquired Abs did not enhance the mortality of 1-day-old neonates born to JEV-Emut mRNA-LNP-immunized mice post ZIKV challenge.

Discussion

These results suggest that optimizing the FL sequence of JEV could significantly reduce the level of JEV/ZIKV-cross-reactive Abs and abrogate the ADE of ZIKV infection, providing a promising strategy to develop effective and safety JEV vaccine.

A Cap-Optimized mRNA Encoding Multiepitope Antigen ESAT6 Induces Robust Cellular and Humoral Immune Responses Against Mycobacterium tuberculosis

Background/Objectives. Tuberculosis is a deadly bacterial disease and the second most common cause of death from monoinfectious diseases worldwide. Comprehensive measures taken by health authorities in various countries in recent decades have saved tens of millions of lives, but the number of new cases of this infection has been steadily increasing in the last few years and already exceeds 10 million new cases annually. The development of new vaccines against tuberculosis is a priority area in the prevention of new cases of the disease. mRNA vaccines have already shown high efficacy against COVID-19 and other viral infections and can currently be considered a promising field of antituberculosis vaccination. In our previous study, we assessed the immunogenicity and protective activity of several types of antituberculosis mRNA vaccines with different 5' untranslated regions, but the efficacy of these vaccines was either comparable with or lower than that of BCG. Methods. Here, we conducted a comprehensive experiment to investigate the effects of cotranscriptional capping conditions and of cap structure on the magnitude of the mRNAs' translation in HEK293T and DC2.4 cells. The most effective cap version was used to create an antituberculosis mRNA vaccine called mEpitope-ESAT6. Results and Conclusions. We compared immunogenicity and protective activity between mEpitope-ESAT6 and BCG and found that the vaccine with the new cap type is more immunogenic than BCG. Nonetheless, the increased immunogenicity did not enhance vaccine-induced protection. Thus, the incorporation of different cap analogs into mRNA allows to modulate the efficacy of mRNA vaccines.

mRNA vaccines for infectious diseases - advances, challenges and opportunities

The concept of mRNA-based vaccines emerged more than three decades ago. Groundbreaking discoveries and technological advancements over the past 20 years have resolved the major roadblocks that initially delayed application of this new vaccine modality. The rapid development of nucleoside-modified COVID-19 mRNA vaccines demonstrated that this immunization platform is easy to develop, has an acceptable safety profile and can be produced at a large scale. The flexibility and ease of antigen design have enabled mRNA vaccines to enter development for a wide range of viruses as well as for various bacteria and parasites. However, gaps in our knowledge limit the development of next-generation mRNA vaccines with increased potency and safety. A deeper understanding of the mechanisms of action of mRNA vaccines, application of novel technologies enabling rational antigen design, and innovative vaccine delivery strategies and vaccination regimens will likely yield potent novel vaccines against a wide range of pathogens.

Cholinized-Polymer Functionalized Lipid-Based Drug Carriers Facilitate Liver Fibrosis Therapy via Ultrafast Liver-Targeting Delivery

Here, we report novel cholinized-polymer functionalized lipid-based nanoparticles (CP-LNPs) for rapid and highly effective delivery of drugs to the liver, achieving targeting within 10 min and nearly 100% efficiency. In this study, CP-LNPs loaded with a promising antifibrotic agent curcumin (CP-LNPs/Cur) significantly improved the stability of curcumin under physiological conditions and its distribution in the liver. In vitro experiments demonstrated that CP-LNPs/Cur effectively suppressed the proliferation and migration of activated hepatic stellate cells (aHSCs), as evidenced by the decreased expression of α-SMA. Moreover, CP-LNPs/Cur attenuated oxidative stress levels in hepatocytes while improving mitochondrial physiological activity. In vivo antifibrosis studies have shown that CP-LNPs/Cur only require a low dose to significantly alleviate liver injury and collagen deposition, thereby preventing the progression of liver fibrosis. These findings indicated that CP-LNPs exhibit great potential in liver fibrosis therapy benefiting from the novel targeting strategy.

mRNA vaccines: a new era in vaccine development

The advent of RNA therapy, particularly through the development of mRNA cancer vaccines, has ushered in a new era in the field of oncology. This article provides a concise overview of the key principles, recent advancements, and potential implications of mRNA cancer vaccines as a groundbreaking modality in cancer treatment. mRNA cancer vaccines represent a revolutionary approach to combatting cancer by leveraging the body's innate immune system. These vaccines are designed to deliver specific mRNA sequences encoding cancer-associated antigens, prompting the immune system to recognize and mount a targeted response against malignant cells. This personalized and adaptive nature of mRNA vaccines holds immense potential for addressing the heterogeneity of cancer and tailoring treatments to individual patients. Recent breakthroughs in the development of mRNA vaccines, exemplified by the success of COVID-19 vaccines, have accelerated their application in oncology. The mRNA platform's versatility allows for the rapid adaptation of vaccine candidates to various cancer types, presenting an agile and promising avenue for therapeutic intervention. Clinical trials of mRNA cancer vaccines have demonstrated encouraging results in terms of safety, immunogenicity, and efficacy. Pioneering candidates, such as BioNTech's BNT111 and Moderna's mRNA-4157, have exhibited promising outcomes in targeting melanoma and solid tumors, respectively. These successes underscore the potential of mRNA vaccines to elicit robust and durable anti-cancer immune responses. While the field holds great promise, challenges such as manufacturing complexities and cost considerations need to be addressed for widespread adoption. The development of scalable and cost-effective manufacturing processes, along with ongoing clinical research, will be pivotal in realizing the full potential of mRNA cancer vaccines. Overall, mRNA cancer vaccines represent a cutting-edge therapeutic approach that holds the promise of transforming cancer treatment. As research progresses, addressing challenges and refining manufacturing processes will be crucial in advancing these vaccines from clinical trials to mainstream oncology practice, offering new hope for patients in the fight against cancer.

A Brighton Collaboration standardized template with key considerations for a benefit-risk assessment for the Comirnaty COVID-19 mRNA vaccine

The Brighton Collaboration Benefit-Risk Assessment of VAccines by TechnolOgy (BRAVATO) Working Group evaluates the safety and other key features of new platform technology vaccines, including nucleic acid (RNA and DNA) vaccines. This manuscript uses the BRAVATO template to report the key considerations for a benefit-risk assessment of the coronavirus disease 2019 (COVID-19) mRNA-based vaccine BNT162b2 (Comirnaty®, or Pfizer-BioNTech COVID-19 vaccine) including the subsequent Original/Omicron BA.1, Original/Omicron BA.4-5 and Omicron XBB.1.5 variant-adapted vaccines developed by BioNTech and Pfizer to protect against COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Initial Emergency Use Authorizations or conditional Marketing Authorizations for the original BNT162b2 vaccine were granted based upon a favorable benefit-risk assessment taking into account clinical safety, immunogenicity, and efficacy data, which was subsequently reconfirmed for younger age groups, and by real world evidence data. In addition, the favorable benefit-risk assessment was maintained for the bivalent vaccines, developed against newly arising SARS-CoV-2 variants, with accumulating clinical trial data.

Evolution of SARS-CoV-2 in the murine central nervous system drives viral diversification

Severe coronavirus disease 2019 and post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are associated with neurological complications that may be linked to direct infection of the central nervous system (CNS), but the selective pressures ruling neuroinvasion are poorly defined. Here we assessed SARS-CoV-2 evolution in the lung versus CNS of infected mice. Higher levels of viral divergence were observed in the CNS than the lung after intranasal challenge with a high frequency of mutations in the spike furin cleavage site (FCS). Deletion of the FCS significantly attenuated virulence after intranasal challenge, with lower viral titres and decreased morbidity compared with the wild-type virus. Intracranial inoculation of the FCS-deleted virus, however, was sufficient to restore virulence. After intracranial inoculation, both viruses established infection in the lung, but dissemination from the CNS to the lung required the intact FCS. Cumulatively, these data suggest a critical role for the FCS in determining SARS-CoV-2 tropism and compartmentalization.

Envelope Protein-Targeting Zika Virus Entry Inhibitors

Zika virus (ZIKV; family, Flaviviridae), which causes congenital Zika syndrome, Guillain-Barré Syndrome, and other severe diseases, is transmitted mainly by mosquitoes; however, the virus can be transmitted through other routes. Among the three structural and seven nonstructural proteins, the surface envelope (E) protein of ZIKV plays a critical role in viral entry and pathogenesis, making it a key target for the development of effective entry inhibitors. This review article describes the life cycle, genome, and encoded proteins of ZIKV, illustrates the structure and function of the ZIKV E protein, summarizes E protein-targeting entry inhibitors (with a focus on those based on natural products and small molecules), and highlights challenges that may potentially hinder the development of effective inhibitors of ZIKV infection. Overall, the article will provide useful guidance for further development of safe and potent ZIKV entry inhibitors targeting the viral E protein.

Ad26.M.Env ZIKV vaccine protects pregnant rhesus macaques and fetuses against Zika virus infection

At the start of the Zika virus (ZIKV) epidemic in 2015, ZIKV spread across South and Central America, and reached parts of the southern United States placing pregnant women at risk for fetal microcephaly, fetal loss, and other adverse pregnancy outcomes associated with congenital ZIKA syndrome (CZS). For this reason, testing of a safe and efficacious ZIKV vaccine remains a global health priority. Here we report that a single immunization with Ad26.M.Env ZIKV vaccine, when administered prior to conception, fully protects pregnant rhesus macaques from ZIKV viral RNA in blood and tissues with no adverse effects in dams and fetuses. Furthermore, vaccination prevents ZIKV distribution to fetal tissues including the brain. ZIKV associated neuropathology was absent in offspring of Ad26.M.Env vaccinated dams, although pathology was limited in fetuses from non-immunized, challenged dams. Vaccine efficacy is associated with induction of ZIKV neutralizing antibodies in pregnant rhesus macaques. These data suggest the feasibility of vaccine prevention of CZS in humans.

A bibliometric insight into nanomaterials in vaccine: trends, collaborations, and future avenues

Background

The emergence of nanotechnology has injected new vigor into vaccine research. Nanovaccine research has witnessed exponential growth in recent years; yet, a comprehensive analysis of related publications has been notably absent.

Objective

This study utilizes bibliometric methodologies to reveal the evolution of themes and the distribution of nanovaccine research.

Methods

Using tools such as VOSviewer, CiteSpace, Scimago Graphica, Pajek, R-bibliometrix, and R packages for the bibliometric analysis and visualization of literature retrieved from the Web of Science database.

Results

Nanovaccine research commenced in 1981. The publication volume exponentially increased, notably in 2021. Leading contributors include the United States, the Chinese Academy of Sciences, the "Vaccine", and researcher Zhao Kai. Other significant contributors comprise China, the University of California, San Diego, Veronique Preat, the Journal of Controlled Release, and the National Natural Science Foundation of China. The USA functions as a central hub for international cooperation. Financial support plays a pivotal role in driving research advancements. Key themes in highly cited articles include vaccine carrier design, cancer vaccines, nanomaterial properties, and COVID-19 vaccines. Among 7402 keywords, the principal nanocarriers include Chitosan, virus-like particles, gold nanoparticles, PLGA, and lipid nanoparticles. Nanovaccine is primarily intended to address diseases including SARS-CoV-2, cancer, influenza, and HIV. Clustering analysis of co-citation networks identifies 9 primary clusters, vividly illustrating the evolution of research themes over different periods. Co-citation bursts indicate that cancer vaccines, COVID-19 vaccines, and mRNA vaccines are pivotal areas of focus for current and future research in nanovaccines. "candidate vaccines," "protein nanoparticle," "cationic lipids," "ionizable lipids," "machine learning," "long-term storage," "personalized cancer vaccines," "neoantigens," "outer membrane vesicles," "in situ nanovaccine," and "biomimetic nanotechnologies" stand out as research interest.

Conclusions

This analysis emphasizes the increasing scholarly interest in nanovaccine research and highlights pivotal recent research themes such as cancer and COVID-19 vaccines, with lipid nanoparticle-mRNA vaccines leading novel research directions.

Library-Assisted Evolution in Eukaryotic Cells Yield Adenine Base Editors with Enhanced Editing Specificity

The current-generation adenine base editor (ABE) ABE8e, which has evolved from the prokaryotic evolution system, exhibits high efficiency in mediating A-to-G conversion and is presumed to be promising for gene therapy. However, its much wider editing window and substantially higher off-target editing activity restricted its applications in precise base editing for therapeutic use. This study uses a library-assisted protein evolution approach using eukaryotic cells to generate ABE variants with improved specificity and reduced off-target editing while maintaining high activity in human cells. The study generated an expanded set of ABEs with efficient editing activities and chose four evolved variants that offered either similar or modestly higher efficiency within a narrower editing window of protospacer position ≈4-7 compared to that of ABE8e in human cells, which would enable minimized bystander editing. Moreover, these variants resulted in reduced off-target editing events when delivered as plasmid or mRNA into human cells. Finally, these variants can install both disease-suppressing mutations and disease-correcting mutations efficiently with minimal undesired bystander editing making them promising approaches for specific therapeutic edits. In summary, the work establishes a mutant-library-assisted protein evolution method in eukaryotic cells and generates alternative ABE variants as efficient tools for precise human genome editing.

Immunoinformatic-guided novel mRNA vaccine designing to elicit immunogenic responses against the endemic Monkeypox virus

Monkeypox virus (MPXV) is an orthopoxvirus, causing zoonotic infections in humans with smallpox-like symptoms. The WHO reported MPXV cases in May 2022 and the outbreak caused significant morbidity threats to immunocompromised individuals and children. Currently, no clinically validated therapies are available against MPXV infections. The present study is based on immunoinformatics approaches to design mRNA-based novel vaccine models against MPXV. Three proteins were prioritized based on high antigenicity, low allergenicity, and toxicity values to predict T- and B-cell epitopes. Lead T- and B-cell epitopes were used to design vaccine constructs, linked with epitope-specific linkers and adjuvant to enhance immune responses. Additional sequences, including Kozak sequence, MITD sequence, tPA sequence, Goblin 5', 3' UTRs, and a poly(A) tail were added to design stable and highly immunogenic mRNA vaccine construct. High-quality structures were predicted by molecular modeling and 3D-structural validation of the vaccine construct. Population coverage and epitope-conservancy speculated broader protection of designed vaccine model against multiple MPXV infectious strains. MPXV-V4 was eventually prioritized based on its physicochemical and immunological parameters and docking scores. Molecular dynamics and immune simulations analyses predicted significant structural stability and binding affinity of the top-ranked vaccine model with immune receptors to elicit cellular and humoral immunogenic responses against the MPXV. The pursuance of experimental and clinical follow-up of these prioritized constructs may lay the groundwork to develop safe and effective vaccine against MPXV.Communicated by Ramaswamy H. Sarma.

N-terminal modification of an LAH4-derived peptide increases mRNA delivery in the presence of serum

The recently developed mRNA-based coronavirus SARS-CoV-2 vaccines highlighted the great therapeutic potential of the mRNA technology. Although the lipid nanoparticles used for the delivery of the mRNA are very efficient, they showed, in some cases, the induction of side effects as well as the production of antibodies directed against particle components. Thus, the development of alternative delivery systems is of great interest in the pursuit of more effective mRNA treatments. In the present work, we evaluated the mRNA transfection capacities of a series of cationic histidine-rich amphipathic peptides derived from LAH4. We found that while the LAH4-A1 peptide was an efficient carrier for mRNA, its activity was highly serum sensitive. Interestingly, modification of this cell penetrating peptide at the N-terminus with two tyrosines or with salicylic acid allowed to confer serum resistance to the carrier.

Vaccine delivery systems and administration routes: Advanced biotechnological techniques to improve the immunization efficacy

Since the first use of vaccine tell the last COVID-19 pandemic caused by spread of SARS-CoV-2 worldwide, the use of advanced biotechnological techniques has accelerated the development of different types and methods for immunization. The last pandemic showed that the nucleic acid-based vaccine, especially mRNA, has an advantage in terms of development time; however, it showed a very critical drawback namely, the higher costs when compared to other strategies, and its inability to protect against new variants. This showed the need of more improvement to reach a better delivery and efficacy. In this review we will describe different vaccine delivery systems including, the most used viral vector, and also variable strategies for delivering of nucleic acid-based vaccines especially lipid-based nanoparticles formulation, polymersomes, electroporation and also the new powerful tools for the delivery of mRNA, which is based on the use of cell-penetrating peptides (CPPs). Additionally, we will also discuss the main challenges associated with each system. Finlay, the efficacy and safety of the vaccines depends not only on the formulations and delivery systems, but also the dosage and route of administration are also important players, therefore we will see the different routes for the vaccine administration including traditionally routes (intramuscular, Transdermal, subcutaneous), oral inhalation or via nasal mucosa, and will describe the advantages and disadvantage of each administration route.

Chikungunya virus vaccine: a decade of progress solving epidemiological dilemma, emerging concepts, and immunological interventions

Chikungunya virus (CHIKV), a single-stranded RNA virus transmitted by Aedes mosquitoes, poses a significant global health threat, with severe complications observed in vulnerable populations. The only licensed vaccine, IXCHIQ, approved by the US FDA, is insufficient to address the growing disease burden, particularly in endemic regions lacking herd immunity. Monoclonal antibodies (mAbs), explicitly targeting structural proteins E1/E2, demonstrate promise in passive transfer studies, with mouse and human-derived mAbs showing protective efficacy. This article explores various vaccine candidates, including live attenuated, killed, nucleic acid-based (DNA/RNA), virus-like particle, chimeric, subunit, and adenovirus vectored vaccines. RNA vaccines have emerged as promising candidates due to their rapid response capabilities and enhanced safety profile. This review underscores the importance of the E1 and E2 proteins as immunogens, emphasizing their antigenic potential. Several vaccine candidates, such as CHIKV/IRES, measles vector (MV-CHIK), synthetic DNA-encoded antibodies, and mRNA-lipid nanoparticle vaccines, demonstrate encouraging preclinical and clinical results. In addition to identifying potential molecular targets for antiviral therapy, the study looks into the roles played by Toll-like receptors, RIG-I, and NOD-like receptors in the immune response to CHIKV. It also offers insights into novel tactics and promising vaccine candidates. This article discusses potential antiviral targets, the significance of E1 and E2 proteins, monoclonal antibodies, and RNA vaccines as prospective Chikungunya virus vaccine candidates.

Immunogenicity and safety of a self-assembling ZIKV nanoparticle vaccine in mice

Zika virus (ZIKV) is a mosquito-borne flavivirus that highly susceptibly causes Guillain-Barré syndrome and microcephaly in newborns. Vaccination is one of the most effective measures for preventing infectious diseases. However, there is currently no approved vaccine to prevent ZIKV infection. Here, we developed nanoparticle (NP) vaccines by covalently conjugating self-assembled 24-subunit ferritin to the envelope structural protein subunit of ZIKV to achieve antigen polyaggregation. The immunogenicityof the NP vaccine was evaluated in mice. Compared to monomer vaccines, the NP vaccine achieved effective antigen presentation, promoted the differentiation of follicular T helper cells in lymph nodes, and induced significantly greater antigen-specific humoral and cellular immune responses. Moreover, the NP vaccine enhanced high-affinity antigen-specific IgG antibody levels, increased secretion of the cytokines IL-4 and IFN-γ by splenocytes, significantly activated T/B lymphocytes, and improved the generation of memory T/B cells. In addition, no significant adverse reactions occurred when NP vaccine was combined with adjuvants. Overall, ferritin-based NP vaccines are safe and effective ZIKV vaccine candidates.

Emerging mRNA Technology for Liver Disease Therapy

Liver diseases have consistently posed substantial challenges to global health. It is crucial to find innovative methods to effectively prevent and treat these diseases. In recent times, there has been an increasing interest in the use of mRNA formulations that accumulate in liver tissue for the treatment of hepatic diseases. In this review, we start by providing a detailed introduction to the mRNA technology. Afterward, we highlight types of liver diseases, discussing their causes, risks, and common therapeutic strategies. Additionally, we summarize the latest advancements in mRNA technology for the treatment of liver diseases. This includes systems based on hepatocyte growth factor, hepatitis B virus antibody, left-right determination factor 1, human hepatocyte nuclear factor α, interleukin-12, methylmalonyl-coenzyme A mutase, etc. Lastly, we provide an outlook on the potential of mRNA technology for the treatment of liver diseases, while also highlighting the various technical challenges that need to be addressed. Despite these difficulties, mRNA-based therapeutic strategies may change traditional treatment methods, bringing hope to patients with liver diseases.

An overview of lipid constituents in lipid nanoparticle mRNA delivery systems

mRNA therapeutics have shown great potential for a broad spectrum of disease treatment. However, the challenges of mRNA's inherent instability and difficulty in cellular entry have hindered its progress in the biomedical field. To address the cellular barriers and deliver mRNA to cells of interest, various delivery systems are designed. Among these, lipid nanoparticles (LNPs) stand out as the most extensively used mRNA delivery systems, particularly following the clinical approvals of corona virus disease 2019 (COVID-19) mRNA vaccines. LNPs are comprised of ionizable cationic lipids, phospholipids, cholesterol, and polyethylene glycol derived lipids (PEG-lipids). In this review, we primarily summarize the recent advancements of the LNP mRNA delivery technology, focusing on the structures of four lipid constituents and their biomedical applications. We delve into structure-activity relationships of the lipids, while also exploring the future prospects and challenges in developing more efficacious mRNA delivery systems. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Japanese encephalitis virus E protein domain III immunization mediates cross-protection against Zika virus in mice via antibodies and CD8+T cells

Zika virus (ZIKV) and Japanese encephalitis virus (JEV) are antigenically related flaviviruses that co-circulate in many countries/territories. The interaction between the two viruses needs to be determined. Recent findings by ourselves and other labs showed that JEV-elicited antibodies (Abs) and CD8+T cells exacerbate and protect against subsequent ZIKV infection, respectively. However, the impact of JEV envelope (E) protein domain III (EDIII)-induced immune responses on ZIKV infection is unclear. We show here that sera from JEV-EDIII-vaccinated mice cross-react with ZIKV-EDIII in vitro, and transfer of the same sera to mice significantly decreases death upon lethal ZIKV infection at a dose-dependent manner. Maternally acquired anti-JEV-EDIII Abs also significantly reduce the mortality of neonatal mice born to JEV-EDIII-immune mothers post ZIKV challenge. Similarly, transfer of ZIKV-EDIII-reactive IgG purified from JEV-vaccinated humans increases the survival of ZIKV-infected mice. Notably, transfer of an extremely low volume of JEV-EDIII-immune sera or ZIKV-EDIII-reactive IgG does not mediate the Ab-mediated enhancement (ADE) of ZIKV infection. Similarly, transfer of JEV-EDIII-elicited CD8+T cells protects recipient mice against ZIKV challenge. These results demonstrate that JEV-EDIII-induced immune components including Abs and T cells have protective roles in ZIKV infection, suggesting EDIII is a promising immunogen for developing effective and safety JEV vaccine.

Biodistribution of lipid nanoparticle, eGFP mRNA and translated protein following subcutaneous administration in mouse

Aim: Increased knowledge of biodistribution and pharmacokinetics of lipid nanoparticle (LNP)-encapsulated mRNA drug components may aid efficacy and safety evaluation.Methods: Mice were subcutaneously administrated LNP encapsulated enhanced green fluorescent protein mRNA and sampled up to 72 h after dosing. LNP, mRNA and translated protein were quantified by LC-MS, branched DNA and ELISA.Results: Highest levels of LNP and mRNA were detected in skin, followed by spleen, but also rapidly distributed to circulation. Translated protein showed high concentration in skin and spleen, but also in liver and kidney across 24 h where the LNP was cleared at 4 h.Conclusion: Subcutaneously dosing LNP encapsulated mRNA in mice resulted in a nonlinear relationship of LNP, mRNA and protein concentration across multiple tissues.

Optimized lipid nanoparticles (LNPs) for organ-selective nucleic acids delivery in vivo

Nucleic acid therapeutics offer tremendous promise for addressing a wide range of common public health conditions. However, the in vivo nucleic acids delivery faces significant biological challenges. Lipid nanoparticles (LNPs) possess several advantages, such as simple preparation, high stability, efficient cellular uptake, endosome escape capabilities, etc., making them suitable for delivery vectors. However, the extensive hepatic accumulation of LNPs poses a challenge for successful development of LNPs-based nucleic acid therapeutics for extrahepatic diseases. To overcome this hurdle, researchers have been focusing on modifying the surface properties of LNPs to achieve precise delivery. The review aims to provide current insights into strategies for LNPs-based organ-selective nucleic acid delivery. In addition, it delves into the general design principles, targeting mechanisms, and clinical development of organ-selective LNPs. In conclusion, this review provides a comprehensive overview to provide guidance and valuable insights for further research and development of organ-selective nucleic acid delivery systems.

Multivalent mRNA-DTP vaccines are immunogenic and provide protection from Bordetella pertussis challenge in mice

Acellular multivalent vaccines for pertussis (DTaP and Tdap) prevent symptomatic disease and infant mortality, but immunity to Bordetella pertussis infection wanes significantly over time resulting in cyclic epidemics of pertussis. The messenger RNA (mRNA) vaccine platform provides an opportunity to address complex bacterial infections with an adaptable approach providing Th1-biased responses. In this study, immunogenicity and challenge models were used to evaluate the mRNA platform with multivalent vaccine formulations targeting both B. pertussis antigens and diphtheria and tetanus toxoids. Immunization with mRNA formulations were immunogenetic, induced antigen specific antibodies, as well as Th1 T cell responses. Upon challenge with either historical or contemporary B. pertussis strains, 6 and 10 valent mRNA DTP vaccine provided protection equal to that of 1/20th human doses of either DTaP or whole cell pertussis vaccines. mRNA DTP immunized mice were also protected from pertussis toxin challenge as measured by prevention of lymphocytosis and leukocytosis. Collectively these pre-clinical mouse studies illustrate the potential of the mRNA platform for multivalent bacterial pathogen vaccines.

The potential use of therapeutics and prophylactic mRNA vaccines in human papillomavirus (HPV)

Cervical cancer (CC) and other malignant malignancies are acknowledged to be primarily caused by persistent human papillomavirus (HPV) infection. Historically, vaccinations against viruses that produce neutralizing antibodies unique to the virus have been an affordable way to manage viral diseases. CC risk is decreased, but not eliminated, by HPV vaccinations. Since vaccinations have been made available globally, almost 90% of HPV infections have been successfully avoided. On the lesions and diseases that are already present, however, no discernible treatment benefit has been shown. As a result, therapeutic vaccines that elicit immune responses mediated by cells are necessary for the treatment of established infections and cancers. mRNA vaccines possess remarkable potential in combating viral diseases and malignancy as a result of their superior industrial production, safety, and efficacy. Furthermore, considering the expeditiousness of production, the mRNA vaccine exhibits promise as a therapeutic approach targeting HPV. Given that the HPV-encoded early proteins, including oncoproteins E6 and E7, are consistently present in HPV-related cancers and pre-cancerous lesions and have crucial functions in the progression and persistence of HPV-related diseases, they serve as ideal targets for therapeutic HPV vaccines. The action mechanism of HPV and HPV-related cancer mRNA vaccines, their recent advancements in clinical trials, and the potential for their therapeutic applications are highlighted in this study, which also offers a quick summary of the present state of mRNA vaccines. Lastly, we highlight a few difficulties with mRNA HPV vaccination clinical practice and provide our thoughts on further advancements in this quickly changing sector. It is expected that mRNA vaccines will soon be produced quickly for clinical HPV prevention and treatment.

Efficient signal sequence of mRNA vaccines enhances the antigen expression to expand the immune protection against viral infection

The signal sequence played a crucial role in the efficacy of mRNA vaccines against virus pandemic by influencing antigen translation. However, limited research had been conducted to compare and analyze the specific mechanisms involved. In this study, a novel approach was introduced by substituting the signal sequence of the mRNA antigen to enhance its immune response. Computational simulations demonstrated that various signal peptides differed in their binding capacities with the signal recognition particle (SRP) 54 M subunit, which positively correlated with antigen translation efficiency. Our data revealed that the signal sequences of tPA and IL-6-modified receptor binding domain (RBD) mRNA vaccines sequentially led to higher antigen expression and elicited more robust humoral and cellular immune protection against the SARS-CoV-2 compared to the original signal sequence. By highlighting the importance of the signal sequence, this research provided a foundational and safe approach for ongoing modifications in signal sequence-antigen design, aiming to optimize the efficacy of mRNA vaccines.

mRNA vaccines against infectious diseases and future direction

Vaccines are used for the control of infectious diseases of animals. Over other types of vaccinations like live attenuated or killed vaccines, mRNA-based vaccines have significant advantages. As only a small portion of the pathogen's genetic material is employed and the dose rate of mRNA-based vaccines is low, there is the least possibility that the pathogen will reverse itself. A carrier or vehicle that shields mRNA-based vaccines from the host's cellular RNases is necessary for their delivery. mRNA vaccines have been shown to be effective and to induce both a cell-mediated immune response and a humoral immune response in clinical trials against various infectious diseases (viral and parasitic) affecting the animals, including rabies, foot and mouth disease, toxoplasmosis, Zikavirus, leishmaniasis, and COVID-19. The current review aims to highlight the use of mRNA-based vaccines both in viral and parasitic diseases of animals.

Modulation of innate immune response to mRNA vaccination after SARS-CoV-2 infection or sequential vaccination in humans

mRNA vaccines are likely to become widely used for the prevention of infectious diseases in the future. Nevertheless, a notable gap exists in mechanistic data, particularly concerning the potential effects of sequential mRNA immunization or preexisting immunity on the early innate immune response triggered by vaccination. In this study, healthy adults, with or without documented prior SARS-CoV-2 infection, were vaccinated with the BNT162b2/Comirnaty mRNA vaccine. Prior infection conferred significantly stronger induction of proinflammatory and type I IFN-related gene signatures, serum cytokines, and monocyte expansion after the prime vaccination. The response to the second vaccination further increased the magnitude of the early innate response in both study groups. The third vaccination did not further increase vaccine-induced inflammation. In vitro stimulation of PBMCs with TLR ligands showed no difference in cytokine responses between groups, or before or after prime vaccination, indicating absence of a trained immunity effect. We observed that levels of preexisting antigen-specific CD4 T cells, antibody, and memory B cells correlated with elements of the early innate response to the first vaccination. Our data thereby indicate that preexisting memory formed by infection may augment the innate immune activation induced by mRNA vaccines.