New Vaccine Technologies for Rapid Response against Emerging, Reemerging Infections and Biological Threats: Lessons from COVID-19 for Future

Vaccination is the most effective method to prevent dangerous infectious diseases and save lives. The expansion of human communication, the rapid spread of emerging infections worldwide, and the creation of dangerous pandemics like COVID-19 is worrying. On the other hand, with the emergence of new technologies such as genetic engineering of microorganisms, genome editing, and synthetic biology, the possibility of abusing these tools for illegal use is the next concern. In this situation, the need for rapid vaccination technologies and programs was given special importance. Recently, new vaccine platforms such as viral vector and mRNA vaccines have shown great promise that they can be used to prepare and protect human lives against dangerous infections. One of the most important factors for vaccination is the rapid development and approval of vaccines. In this review, we have given a perspective view of new vaccine technologies to rapidly develop vaccine s to combat emerging infections and the biodefence against biological criminals. © 2023 The Author(s).

Viral vector vaccines: efforts to develop vaccines against emerging infectious diseases

Vaccines are one of the most effective means of preventing viral infections. Since Edward Jenner invented the world's first vaccine in 1796, against smallpox, various types of vaccine have been developed, including inactivated vaccines, attenuated live vaccines, recombinant protein vaccines, viral vector vaccines and nucleic acid vaccines. Viral vector vaccines and nucleic acid vaccines （mRNA vaccines and DNA vaccines） have been developed most recently. In these vaccines, genes encoding viral proteins that serve as antigens are introduced into the body. The viral vector is an excellent vaccine delivery system that efficiently delivers antigen genes to target cells, and has been utilized for vaccine development against a variety of emerging infectious diseases, including AIDS, malaria, Ebola hemorrhagic fever, dengue fever, and most recently COVID-19. Here, we provide an overview of viral vector vaccines and discuss recent efforts to develop vaccines against emerging infectious diseases.Alternate :抄録ウイルス性感染症を予防するうえで、ワクチンは最も有効な手段の一つである。1976年、エドワード・ジェンナーが世界初のワクチンである種痘を発明して以来、さまざまなウイルス性感染症に対して、不活化ワクチン、弱毒生ワクチン、組換えタンパクワクチン、ウイルスベクターワクチン、核酸ワクチンなど、多様なプラットフォームに基づくワクチン開発が進められてきた。本稿では、数あるワクチンプラットフォームの中から、ウイルスベクターワクチンに着目して、いくつかの例をあげて概説するとともに、近年、国際的な問題となっている新興感染症に対するワクチン開発などの取り組みについても述べる。

Safety of COVID-19 vaccines in multiple sclerosis: A systematic review and meta-analysis.

BACKGROUND: Data are sparse regarding the safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with multiple sclerosis (MS). OBJECTIVE: To estimate (1) the pooled proportion of MS patients experiencing relapse among vaccine recipients; (2) the rate of transient neurological worsening, adverse events, and serious adverse events; (3) the previous outcomes of interest for different SARS-CoV-2 vaccine types. METHODS: Systematic review and meta-analysis of pharmacovigilance registries and observational studies. RESULTS: Nineteen observational studies comprising 14,755 MS patients who received 23,088 doses of COVID-19 vaccines were included. Mean age was 43.3 years (95% confidence interval (CI): 40-46.6); relapsing-remitting, secondary-progressive, primary-progressive MS and clinically isolated syndrome were diagnosed in 82.6% (95% CI: 73.9-89.8), 12.6% (95% CI: 6.3-20.8), 6.7% (95% CI: 4.2-9.9), and 2.9% (95% CI: 1-5.9) of cases, respectively. The pooled proportion of MS patients experiencing relapse at a mean time interval of 20 days (95% CI: 12-28.2) from vaccination was 1.9% (95% CI: 1.3%-2.6%; I2 = 78%), with the relapse risk being independent of the type of administered SARS-CoV-2-vaccine (p for subgroup differences = 0.7 for messenger RNA (mRNA), inactivated virus, and adenovector-based vaccines). After vaccination, transient neurological worsening was observed in 4.8% (95% CI: 2.3%-8.1%) of patients. Adverse events and serious adverse events were reported in 52.8% (95% CI: 46.7%-58.8%) and 0.1% (95% CI: 0%-0.2%) of vaccinations, respectively. CONCLUSION: COVID-19 vaccination does not appear to increase the risk of relapse and serious adverse events in MS. Weighted against the risks of SARS-CoV-2-related complications and MS exacerbations, these safety data provide compelling pro-vaccination arguments for MS patients.

rAAV expressing recombinant antibody for emergency prevention and long-term prophylaxis of COVID-19.

Introduction: Numerous agents for prophylaxis of SARS-CoV-2-induced diseases are currently registered for the clinical use. Formation of the immunity happens within several weeks following vaccine administration which is their key disadvantage. In contrast, drugs based on monoclonal antibodies, enable rapid passive immunization and therefore can be used for emergency pre- and post-exposure prophylaxis of COVID-19. However rapid elimination of antibody-based drugs from the circulation limits their usage for prolonged pre-exposure prophylaxis. Methods: In current work we developed a recombinant adeno-associated viral vector (rAAV), expressing a SARS-CoV-2 spike receptor-binding domain (RBD)-specific antibody P2C5 fused with a human IgG1 Fc fragment (P2C5-Fc) using methods of molecular biotechnology and bioprocessing. Results and discussions: A P2C5-Fc antibody expressed by a proposed rAAV (rAAV-P2C5-Fc) was shown to circulate within more than 300 days in blood of transduced mice and protect animals from lethal SARS-CoV-2 virus (B.1.1.1 and Omicron BA.5 variants) lethal dose of 105 TCID50. In addition, rAAV-P2C5-Fc demonstrated 100% protective activity as emergency prevention and long-term prophylaxis, respectively. It was also demonstrated that high titers of neutralizing antibodies to the SARS-CoV-2 virus were detected in the blood serum of animals that received rAAV-P2C5-Fc for more than 10 months from the moment of administration.Our data therefore indicate applicability of an rAAV for passive immunization and induction of a rapid long-term protection against various SARS-CoV-2 variants.

A systematic review and meta-analysis of the seroconversion rates and adverse effects of COVID-19 mRNA vaccine and COVID-19 viral vector vaccine in kidney transplant recipient patients.

Patients received kidney transplantation (KTR) have a low seroconversion rate after vaccination. Our objective was to compare the seroconversion rates and adverse effects of additional different vaccinations in KTR patients in existing studies. Databases such as PubMed, Cochrane Library, Web of Science, Embase, ClinicalTrials.gov and others. Three high-quality RCT were included and showed no statistical difference in seroconversion rates between the two vaccines (RR = 0.93[0.76,1.13]). There was no statistical difference in seroconversion rates between the sexes, for men (RR = 0.93[0.69,1.25]) and women (RR = 0.91[0.62,1.33]). Among the adverse effects there was no statistically significant difference in fever (RR = 1.06[0.44,2.57]), while for injection site pain there was a statistically significant difference (RR = 1.14[1.18,1.84]). There was no significant difference in seroconversion rates in patients with KTR who received the two additional vaccines. Patients injected with the viral vector vaccine were less painful than those injected with the mRNA vaccine.

Vaccine effectiveness against transmission of alpha, delta and omicron SARS-COV-2-infection, Belgian contact tracing, 2021-2022.

OBJECTIVES: Vaccine effectiveness against transmission (VET) of SARS-CoV-2-infection can be estimated from secondary attack rates observed during contact tracing. We estimated VET, the vaccine-effect on infectiousness of the index case and susceptibility of the high-risk exposure contact (HREC). METHODS: We fitted RT-PCR-test results from HREC to immunity status (vaccine schedule, prior infection, time since last immunity-conferring event), age, sex, calendar week of sampling, household, background positivity rate and dominant VOC using a multilevel Bayesian regression-model. We included Belgian data collected between January 2021 and January 2022. RESULTS: For primary BNT162b2-vaccination we estimated initial VET at 96% (95%CI 95-97) against Alpha, 87% (95%CI 84-88) against Delta and 31% (95%CI 25-37) against Omicron. Initial VET of booster-vaccination (mRNA primary and booster-vaccination) was 87% (95%CI 86-89) against Delta and 68% (95%CI 65-70) against Omicron. The VET-estimate against Delta and Omicron decreased to 71% (95%CI 64-78) and 55% (95%CI 46-62) respectively, 150-200 days after booster-vaccination. Hybrid immunity, defined as vaccination and documented prior infection, was associated with durable and higher or comparable (by number of antigen exposures) protection against transmission. CONCLUSIONS: While we observed VOC-specific immune-escape, especially by Omicron, and waning over time since immunization, vaccination remained associated with a reduced risk of SARS-CoV-2-transmission.

Viral vector vaccines: ef forts to develop vaccines against emerging infectious diseases.

Vaccines are one of the most effective means of preventing viral infections. Since Edward Jenner invented the world's first vaccine in 1796, against smallpox, various types of vaccine have been DDS developed, including inactivated vaccines, attenuated live vaccines, recombinant protein vaccines, viral vector vaccines and nucleic acid vaccines. Viral vector vaccines and nucleic acid vaccines mRNA vaccines and DNA vaccineshave been developed most recently. In these vaccines, genes encoding viral proteins that serve as antigens are introduced into the body. The viral vector is an excellent vaccine delivery system that efficiently delivers antigen genes to target cells, and has been utilized for vaccine development against a variety of emerging infectious diseases, including AIDS, malaria, Ebola hemorrhagic fever, dengue fever, and most recently COVID-19 . Here, we provide an overview of viral vector vaccines and discuss recent efforts to develop vaccines against emerging infectious diseases.Copyright © 2022, Japan Society of Drug Delivery System. All rights reserved.

Viral vector vaccines: ef forts to develop vaccines against emerging infectious diseases.

Vaccines are one of the most effective means of preventing viral infections. Since Edward Jenner invented the world's first vaccine in 1796, against smallpox, various types of vaccine have been DDS developed, including inactivated vaccines, attenuated live vaccines, recombinant protein vaccines, viral vector vaccines and nucleic acid vaccines. Viral vector vaccines and nucleic acid vaccines (mRNA vaccines and DNA vaccines)have been developed most recently. In these vaccines, genes encoding viral proteins that serve as antigens are introduced into the body. The viral vector is an excellent vaccine delivery system that efficiently delivers antigen genes to target cells, and has been utilized for vaccine development against a variety of emerging infectious diseases, including AIDS, malaria, Ebola hemorrhagic fever, dengue fever, and most recently COVID-19 . Here, we provide an overview of viral vector vaccines and discuss recent efforts to develop vaccines against emerging infectious diseases.Copyright © 2022, Japan Society of Drug Delivery System. All rights reserved.

Viral vector vaccines: ef forts to develop vaccines against emerging infectious diseases.

Vaccines are one of the most effective means of preventing viral infections. Since Edward Jenner invented the world's first vaccine in 1796, against smallpox, various types of vaccine have been DDS developed, including inactivated vaccines, attenuated live vaccines, recombinant protein vaccines, viral vector vaccines and nucleic acid vaccines. Viral vector vaccines and nucleic acid vaccines (mRNA vaccines and DNA vaccines)have been developed most recently. In these vaccines, genes encoding viral proteins that serve as antigens are introduced into the body. The viral vector is an excellent vaccine delivery system that efficiently delivers antigen genes to target cells, and has been utilized for vaccine development against a variety of emerging infectious diseases, including AIDS, malaria, Ebola hemorrhagic fever, dengue fever, and most recently COVID-19 . Here, we provide an overview of viral vector vaccines and discuss recent efforts to develop vaccines against emerging infectious diseases.Copyright © 2022, Japan Society of Drug Delivery System. All rights reserved.

Comparison of vector elements and process conditions in transient and stable suspension HEK293 platforms using SARS-CoV-2 receptor binding domain as a model protein.

BACKGROUND: Mammalian cell lines are frequently used as protein expression hosts because of their ability to correctly fold and assemble complex proteins, produce them at high titers, and confer post-translational modifications (PTMs) critical to proper function. Increasing demand for proteins with human-like PTMs, particularly viral proteins and vectors, have made human embryonic kidney 293 (HEK293) cells an increasingly popular host. The need to engineer more productive HEK293 platforms and the ongoing nature of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic presented an opportunity to study strategies to improve viral protein expression in transient and stable HEK293 platforms. RESULTS: Initial process development was done at 24 deep well plate (DWP) -scale to screen transient processes and stable clonal cell lines for recombinant SARS-CoV-2 receptor binding domain (rRBD) titer. Nine DNA vectors that drove rRBD production under different promoters and optionally contained Epstein-Barr virus (EBV) elements to promote episomal expression were screened for transient rRBD production at 37 °C or 32 °C. Use of the cytomegalovirus (CMV) promoter to drive expression at 32 °C led to the highest transient protein titers, but inclusion of episomal expression elements did not augment titer. In parallel, four clonal cell lines with titers higher than that of the selected stable pool were identified in a batch screen. Flask-scale transient transfection and stable fed-batch processes were then established that produced rRBD up to 100 mg/L and 140 mg/L, respectively. While a bio-layer interferometry (BLI) assay was crucial for efficiently screening DWP batch titers, an enzyme-linked immunosorbent assay (ELISA) was used to compare titers from the flask-scale batches due to varying matrix effects from different cell culture media compositions. CONCLUSION: Comparing yields from the flask-scale batches revealed that stable fed-batch cultures produced up to 2.1x more rRBD than transient processes. The stable cell lines developed in this work are the first reported clonal, HEK293-derived rRBD producers and have titers up to 140 mg/L. As stable production platforms are more economically favorable for long-term protein production at large scales, investigation of strategies to increase the efficiency of high-titer stable cell line generation in Expi293F or other HEK293 hosts is warranted.

Extracellular Vesicle-Based SARS-CoV-2 Vaccine.

Messenger ribonucleic acid (RNA) vaccines are mainly used as SARS-CoV-2 vaccines. Despite several issues concerning storage, stability, effective period, and side effects, viral vector vaccines are widely used for the prevention and treatment of various diseases. Recently, viral vector-encapsulated extracellular vesicles (EVs) have been suggested as useful tools, owing to their safety and ability to escape from neutral antibodies. Herein, we summarize the possible cellular mechanisms underlying EV-based SARS-CoV-2 vaccines.

Viral Vectors in Gene Therapy: Where Do We Stand in 2023?

Viral vectors have been used for a broad spectrum of gene therapy for both acute and chronic diseases. In the context of cancer gene therapy, viral vectors expressing anti-tumor, toxic, suicide and immunostimulatory genes, such as cytokines and chemokines, have been applied. Oncolytic viruses, which specifically replicate in and kill tumor cells, have provided tumor eradication, and even cure of cancers in animal models. In a broader meaning, vaccine development against infectious diseases and various cancers has been considered as a type of gene therapy. Especially in the case of COVID-19 vaccines, adenovirus-based vaccines such as ChAdOx1 nCoV-19 and Ad26.COV2.S have demonstrated excellent safety and vaccine efficacy in clinical trials, leading to Emergency Use Authorization in many countries. Viral vectors have shown great promise in the treatment of chronic diseases such as severe combined immunodeficiency (SCID), muscular dystrophy, hemophilia, ß-thalassemia, and sickle cell disease (SCD). Proof-of-concept has been established in preclinical studies in various animal models. Clinical gene therapy trials have confirmed good safety, tolerability, and therapeutic efficacy. Viral-based drugs have been approved for cancer, hematological, metabolic, neurological, and ophthalmological diseases as well as for vaccines. For example, the adenovirus-based drug Gendicine® for non-small-cell lung cancer, the reovirus-based drug Reolysin® for ovarian cancer, the oncolytic HSV T-VEC for melanoma, lentivirus-based treatment of ADA-SCID disease, and the rhabdovirus-based vaccine Ervebo against Ebola virus disease have been approved for human use.

Adenoviral Vector-Based Vaccine Platform for COVID-19: Current Status.

The coronavirus disease (COVID-19) breakout had an unimaginable worldwide effect in the 21st century, claiming millions of lives and putting a huge burden on the global economy. The potential developments in vaccine technologies following the determination of the genetic sequence of SARS-CoV-2 and the increasing global efforts to bring potential vaccines and therapeutics into the market for emergency use have provided a small bright spot to this tragic event. Several intriguing vaccine candidates have been developed using recombinant technology, genetic engineering, and other vaccine development technologies. In the last decade, a vast amount of the vaccine development process has diversified towards the usage of viral vector-based vaccines. The immune response elicited by such vaccines is comparatively higher than other approved vaccine candidates that require a booster dose to provide sufficient immune protection. The non-replicating adenoviral vectors are promising vaccine carriers for infectious diseases due to better yield, cGMP-friendly manufacturing processes, safety, better efficacy, manageable shipping, and storage procedures. As of April 2022, the WHO has approved a total of 10 vaccines around the world for COVID-19 (33 vaccines approved by at least one country), among which three candidates are adenoviral vector-based vaccines. This review sheds light on the developmental summary of all the adenoviral vector-based vaccines that are under emergency use authorization (EUA) or in the different stages of development for COVID-19 management.

Increase in the Immune Response in Balb/c Mice after the Co-Administration of a Vector-Based COVID-19 Vaccine with Cytosine Phosphoguanine Oligodeoxynucleotide.

The effects of cytosine phosphoguanine oligodeoxynucleotides (CPG ODNs) on immune response have been demonstrated for different vaccines; however, such information is limited for the vector-based Coronavirus disease 2019 (COVID-19). This paper aims to demonstrate the potential effect of CPG ODNs on immunological response against the vector-based COVID-19 vaccine on Balb/c mice using a JNJ-78436735 Ad26.COV2-S recombinant as a model vaccine. A total of 18 BALB/c mice clustered into six groups were used. All groups were observed for 14- and 28-days post immunization. Qualitative determination of IgG was performed using indirect Enzyme-Linked Immunosorbent Assay (ELISA) and qPCR for cytokine profiling. A significant (p ≤ 0.001) rise in antibody response was observed for groups 3 and 4, who also showed increased expression levels of Tumor Necrosis Factor (TNF) and Interferon Gamma (IFN-γ). Immunological parameters for toxicity were normal in all treatment groups. We conclude that supplementing vector-based COVID-19 vaccines with CpG ODNs has the potential to boost the body's immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

SARS-CoV-2 Vaccines: Types, Working Principle, and Its Impact on Thrombosis and Gastrointestinal Disorders.

In the current scenario of the coronavirus pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), considerable efforts have been made to control the pandemic by the development of a strong immune system through massive vaccination. Just after the discovery of the genetic sequences of SARS-CoV-2, the development of vaccines became the prime focus of scientists around the globe. About 200 SARS-CoV-2 candidate vaccines have already been entered into preclinical and clinical trials. Various traditional and novel approaches are being utilized as a broad range of platforms. Viral vector (replicating and non-replicating), nucleic acid (DNA and RNA), recombinant protein, virus-like particle, peptide, live attenuated virus, an inactivated virus approaches are the prominent attributes of the vaccine development. This review article includes the current knowledge about the platforms used for the development of different vaccines, their working principles, their efficacy, and the impacts of COVID-19 vaccines on thrombosis. We provide a detailed description of the vaccines that are already approved by administrative authorities. Moreover, various strategies utilized in the development of emerging vaccines that are in the trial phases along with their mode of delivery have been discussed along with their effect on thrombosis and gastrointestinal disorders.

Newcastle Disease Virus as a Vaccine Vector for SARS-CoV-2.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in more than 16 million infections and more than 600,000 deaths worldwide. There is an urgent need to develop a safe and effective vaccine against SARS-CoV-2. Currently, several strategies are being pursued to develop a safe and effective SARS-CoV-2 vaccine. However, each vaccine strategy has distinct advantages and disadvantages. Therefore, it is important to evaluate multiple vaccine platforms to select the most efficient vaccine platform for SARS-CoV-2. In this regard, Newcastle disease virus (NDV), an avian virus, has several well-suited properties for development of a vector vaccine against SARS-CoV-2. Here, we elaborate on the idea of considering NDV as a vaccine vector for SARS-CoV-2.

Reactogenicity of COVID-19 Vaccines in Patients With a History of COVID-19 Infection: A Survey Conducted in Pakistan.

Introduction As coronavirus disease 2019 (COVID-19) immunizations become more common, concerns about their safety and reactogenicity have grown. It is important to assess and analyze the post-vaccination side effects of several COVID-19 vaccines that have been licensed in Pakistan. Methods and results A comparative cross-sectional study was conducted between October 2021 and January 2022 to collect data on the side effects produced by different COVID-19 vaccines. An online survey was conducted to gather data on participants' demographics, clinical profiles, COVID-19 profiles as well as the intensity and side effects of COVID-19 vaccines. Statistical Package for the Social Sciences (SPSS) version 22.0 (IBM Corp., Armonk, NY) was used to analyze the data collected. Out of 421 participants, 63.2% were males, 36.8% of participants received messenger RNA (mRNA) vaccine, 33.2% received viral vector vaccine, 29.9% received inactivated vaccine, and further 71.7% of the total subjects were completely immunized. The majority of the symptoms were mild to moderate in degree. Approximately, 0.7% of the individuals reported experiencing serious adverse effects. Injection site pain (35.9%) was noted to be the most remarkable post-vaccination side effect followed by fever (33.2%) and fatigue (23.1%). Prior COVID-19 infection was not associated with the severity of any COVID-19 vaccine-related side effect (p > 0.05), except dyspnea. Younger participants and the female gender were substantially linked to post-vaccination adverse effects. Conclusion In comparison to viral vector and inactivated vaccines, our data suggest that the mRNA-based vaccination causes more severe adverse effects, and the majority of them were mild to moderate in severity. Participants who had previously contracted COVID-19 were not at a higher risk of developing additional vaccine-related side effects.

Research Progress of Non-viral Vector Delivery System for mRNA Vaccines

With the outbreak of COVID-19, the world urgently needs a large number of effective vaccines to deal with this disaster. mRNA vaccines are safe and have short development cycle, which can fill the gap between epidemic diseases and vaccine shortages. So mRNA has become one of the most potential vaccines at present and has attracted attention in the field of infectious diseases and tumors. Technological innovation has greatly improved the shortcomings of mRNA, such as instability and low translation efficiency. However, delivering mRNA to target cells safely and efficiently is still a major challenge that hinders the progress in mRNA research. Hopefully, delivery systems have put forward many effective solutions. This review focuses on the non-viral vector delivery system for mRNA vaccine delivery in vivo, and the application of mRNA in infectious disease and tumor vaccine, in order to provide reference for research and development of mRNA vaccines. © 2022, China Biotechnology Press. All rights reserved.

Intranasal pediatric parainfluenza virus-vectored SARS-CoV-2 vaccine is protective in monkeys.

Pediatric SARS-CoV-2 vaccines are needed that elicit immunity directly in the airways as well as systemically. Building on pediatric parainfluenza virus vaccines in clinical development, we generated a live-attenuated parainfluenza-virus-vectored vaccine candidate expressing SARS-CoV-2 prefusion-stabilized spike (S) protein (B/HPIV3/S-6P) and evaluated its immunogenicity and protective efficacy in rhesus macaques. A single intranasal/intratracheal dose of B/HPIV3/S-6P induced strong S-specific airway mucosal immunoglobulin A (IgA) and IgG responses. High levels of S-specific antibodies were also induced in serum, which efficiently neutralized SARS-CoV-2 variants of concern of alpha, beta, and delta lineages, while their ability to neutralize Omicron sub-lineages was lower. Furthermore, B/HPIV3/S-6P induced robust systemic and pulmonary S-specific CD4+ and CD8+ T cell responses, including tissue-resident memory cells in the lungs. Following challenge, SARS-CoV-2 replication was undetectable in airways and lung tissues of immunized macaques. B/HPIV3/S-6P will be evaluated clinically as pediatric intranasal SARS-CoV-2/parainfluenza virus type 3 vaccine.