scholarly journals Inter-Lineage Variation of Lassa Virus Glycoprotein Epitopes: A Challenge to Lassa Virus Vaccine Development

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 386
Author(s):  
Francis Ifedayo Ibukun
Keyword(s):  
B Cell ◽  
Viral Vectors ◽  
Vaccine Development ◽  
Lassa Virus ◽  
High Genetic Diversity ◽  
Vaccine Candidates ◽  
Multiple Alignments ◽  
Considerable Morbidity ◽  
Lineage Iv ◽  
Homologous Challenge

Lassa virus (LASV), which causes considerable morbidity and mortality annually, has a high genetic diversity across West Africa. LASV glycoprotein (GP) expresses this diversity, but most LASV vaccine candidates utilize only the Lineage IV LASV Josiah strain GP antigen as an immunogen and homologous challenge with Lineage IV LASV. In addition to the sequence variation amongst the LASV lineages, these lineages are also distinguished in their presentations. Inter-lineage variations within previously mapped B-cell and T-cell LASV GP epitopes and the breadth of protection in LASV vaccine/challenge studies were examined critically. Multiple alignments of the GP primary sequence of strains from each LASV lineage showed that LASV GP has diverging degrees of amino acid conservation within known epitopes among LASV lineages. Conformational B-cell epitopes spanning different sites in GP subunits were less impacted by LASV diversity. LASV GP diversity should influence the approach used for LASV vaccine design. Expression of LASV GP on viral vectors, especially in its prefusion configuration, has shown potential for protective LASV vaccines that can overcome LASV diversity. Advanced vaccine candidates should demonstrate efficacy against all LASV lineages for evidence of a pan-LASV vaccine.

scholarly journals Developmental Landscape of Potential Vaccine Candidates Based on Viral Vector for Prophylaxis of COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Rajashri Bezbaruah ◽  
Pobitra Borah ◽  
Bibhuti Bhushan Kakoti ◽  
Nizar A. Al-Shar’I ◽  
Balakumar Chandrasekaran ◽  
...  
Keyword(s):  
Viral Vectors ◽  
Ebola Virus ◽  
Vaccine Development ◽  
Viral Vector ◽  
World Health ◽  
Prolonged Incubation ◽  
Vaccine Candidates ◽  
Vector Vaccine ◽  
Dna And Rna ◽  
Viral Vector Vaccine

Severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, arose at the end of 2019 as a zoonotic virus, which is the causative agent of the novel coronavirus outbreak COVID-19. Without any clear indications of abatement, the disease has become a major healthcare threat across the globe, owing to prolonged incubation period, high prevalence, and absence of existing drugs or vaccines. Development of COVID-19 vaccine is being considered as the most efficient strategy to curtail the ongoing pandemic. Following publication of genetic sequence of SARS-CoV-2, globally extensive research and development work has been in progress to develop a vaccine against the disease. The use of genetic engineering, recombinant technologies, and other computational tools has led to the expansion of several promising vaccine candidates. The range of technology platforms being evaluated, including virus-like particles, peptides, nucleic acid (DNA and RNA), recombinant proteins, inactivated virus, live attenuated viruses, and viral vectors (replicating and non-replicating) approaches, are striking features of the vaccine development strategies. Viral vectors, the next-generation vaccine platforms, provide a convenient method for delivering vaccine antigens into the host cell to induce antigenic proteins which can be tailored to arouse an assortment of immune responses, as evident from the success of smallpox vaccine and Ervebo vaccine against Ebola virus. As per the World Health Organization, till January 22, 2021, 14 viral vector vaccine candidates are under clinical development including 10 nonreplicating and four replicating types. Moreover, another 39 candidates based on viral vector platform are under preclinical evaluation. This review will outline the current developmental landscape and discuss issues that remain critical to the success or failure of viral vector vaccine candidates against COVID-19.

scholarly journals Perspectives on RNA Vaccine Candidates for COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Pobitra Borah ◽  
Pran Kishore Deb ◽  
Nizar A. Al-Shar’i ◽  
Lina A. Dahabiyeh ◽  
Katharigatta N. Venugopala ◽  
...  
Keyword(s):  
Viral Vectors ◽  
Vaccine Development ◽  
Lessons Learned ◽  
Public Health Care ◽  
World Health ◽  
Genetic Sequencing ◽  
Vaccine Candidates ◽  
Clinical Investigations ◽  
Current Outbreak ◽  
Health Organization

With the current outbreak caused by SARS-CoV-2, vaccination is acclaimed as a public health care priority. Rapid genetic sequencing of SARS-CoV-2 has triggered the scientific community to search for effective vaccines. Collaborative approaches from research institutes and biotech companies have acknowledged the use of viral proteins as potential vaccine candidates against COVID-19. Nucleic acid (DNA or RNA) vaccines are considered the next generation vaccines as they can be rapidly designed to encode any desirable viral sequence including the highly conserved antigen sequences. RNA vaccines being less prone to host genome integration (cons of DNA vaccines) and anti-vector immunity (a compromising factor of viral vectors) offer great potential as front-runners for universal COVID-19 vaccine. The proof of concept for RNA-based vaccines has already been proven in humans, and the prospects for commercialization are very encouraging as well. With the emergence of COVID-19, mRNA-1273, an mRNA vaccine developed by Moderna, Inc. was the first to enter human trials, with the first volunteer receiving the dose within 10 weeks after SARS-CoV-2 genetic sequencing. The recent interest in mRNA vaccines has been fueled by the state of the art technologies that enhance mRNA stability and improve vaccine delivery. Interestingly, as per the “Draft landscape of COVID-19 candidate vaccines” published by the World Health Organization (WHO) on December 29, 2020, seven potential RNA based COVID-19 vaccines are in different stages of clinical trials; of them, two candidates already received emergency use authorization, and another 22 potential candidates are undergoing pre-clinical investigations. This review will shed light on the rationality of RNA as a platform for vaccine development against COVID-19, highlighting the possible pros and cons, lessons learned from the past, and the future prospects.

scholarly journals Recent Advances in Zika Virus Vaccines

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 631 ◽  
Author(s):  
Himanshu Garg ◽  
Tugba Mehmetoglu-Gurbuz ◽  
Anjali Joshi
Keyword(s):  
Zika Virus ◽  
Viral Vectors ◽  
Vaccine Development ◽  
Treatment Strategies ◽  
Target Population ◽  
Primary Objective ◽  
Vaccine Candidates ◽  
Diagnostic Assays ◽  
Recent Advances ◽  
Short Period

The recent outbreaks of Zika virus (ZIKV) infections and associated microcephaly in newborns has resulted in an unprecedented effort by researchers to target this virus. Significant advances have been made in developing vaccine candidates, treatment strategies and diagnostic assays in a relatively short period of time. Being a preventable disease, the first line of defense against ZIKV would be to vaccinate the highly susceptible target population, especially pregnant women. Along those lines, several vaccine candidates including purified inactivated virus (PIV), live attenuated virus (LAV), virus like particles (VLP), DNA, modified RNA, viral vectors and subunit vaccines have been in the pipeline with several advancing to clinical trials. As the primary objective of Zika vaccination is the prevention of vertical transmission of the virus to the unborn fetus, the safety and efficacy requirements for this vaccine remain unique when compared to other diseases. This review will discuss these recent advances in the field of Zika vaccine development.

scholarly journals Self-Replicating RNA Viruses for Vaccine Development Against Infectious Diseases and Cancer

2021 ◽  
Author(s):  
Kenneth Lundstrom
Keyword(s):  
Clinical Trials ◽  
Infectious Diseases ◽  
Immune Responses ◽  
Measles Virus ◽  
Viral Vectors ◽  
Ebola Virus ◽  
Vaccine Development ◽  
Rna Viruses ◽  
Vaccine Candidates ◽  
Vector Systems

Alphaviruses, flaviviruses, measles viruses and rhabdoviruses are enveloped single-stranded RNA viruses, which have been engineered as expression vector systems for recombinant protein expression and vaccine development. Due to the presence of non-structural genes encoding the replicase complex, a 200,000-fold amplification of viral RNA occurs in the cytoplasm of infected cells providing extreme transgene expression levels, which is why they are named self-replicating RNA viruses. Expression of surface proteins of pathogens causing infectious disease and tumor antigens provide the basis for vaccine development against infectious diseases and cancer. The self-replicating RNA viral vectors can be administered as replicon RNA, recombinant viral particles, or layered DNA/RNA replicons. Self-replicating RNA viral vectors have been applied for vaccine development against influenza virus, HIV, hepatitis B virus, human papilloma virus, Ebola virus and recently coronaviruses, especially SARS-CoV-2 the causative agent of the COVID-19 pandemic. Measles virus and rhabdovirus vector-based SARS-CoV-2 vaccine candidates have been subjected to clinical trials. Moreover, RNA vaccine candidates based on self-amplifying alphaviruses have also been evaluated in clinical settings. Various cancers such as brain, breast, lung, ovarian, prostate cancer and melanoma have also been targeted for vaccine development. Robust immune responses and protection have been demonstrated in animal models. Clinical trials have shown good safety and target-specific immune responses. Ervebo, the VSV-based vaccine against Ebola virus disease has been approved for human use.

scholarly journals CEPI: Driving Progress Toward Epidemic Preparedness and Response

2019 ◽  
Vol 41 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Dimitrios Gouglas ◽  
Mario Christodoulou ◽  
Stanley A Plotkin ◽  
Richard Hatchett
Keyword(s):  
Vaccine Development ◽  
Response Times ◽  
Sustainable Manufacturing ◽  
Nipah Virus ◽  
Lassa Virus ◽  
Valley Fever ◽  
Regulatory Pathways ◽  
Vaccine Candidates ◽  
Emergency Situations ◽  
Leading Role

Abstract The Coalition for Epidemic Preparedness Innovations (CEPI) was formed in the aftermath of the 2014–2015 Ebola outbreak in west Africa to support the development of vaccines that could improve the world’s preparedness against outbreaks of epidemic infectious diseases. Since its launch in 2017, CEPI has mobilized more than US$750 million to support its mission to develop vaccines against agents such as Lassa virus, Middle East respiratory syndrome coronavirus, and Nipah virus, as well as several rapid-response vaccine platforms to accelerate response times to unexpected epidemic threats. CEPI has also played a leading role in fostering institutional partnerships between public- and private-sector organizations to optimize allocation of resources for vaccine development against its priority pathogens. CEPI’s priorities include diversification of its current vaccine research and development investment portfolio to include additional pathogens, such as Rift Valley fever and chikungunya; establishment of technical and regulatory pathways for vaccine development across CEPI’s portfolio; development of sustainable manufacturing solutions for vaccine candidates nearing completion of safety and immunogenicity testing in humans; and creation of investigational stockpiles of its vaccine candidates for use in emergency situations. This commentary provides an overview of the global health challenges CEPI was established to address and its achievements to date, and indicates priorities for funding and coordination in the coming years.

scholarly journals Stages in COVID-19 vaccine development: The Nemesis, the Hubris and the Elpis

2020 ◽  
Vol 4 (1) ◽  
pp. 126-135
Author(s):  
Nikhra Vinod
Keyword(s):  
Clinical Trials ◽  
Viral Vectors ◽  
Vaccine Development ◽  
Risk Groups ◽  
Phase Iii ◽  
Vaccine Hesitancy ◽  
Effective Vaccine ◽  
Vaccine Candidates ◽  
Phase Iii Clinical Trials ◽  
And Control

The nemesis: SARS-CoV-2 pandemic: Leaving in its wake millions of infections, accompanied by an immense magnitude of morbidity and multitude of mortality, and an unfathomable economic toll, the COVID-19 pandemic has led to a global calamity. An effective and safe COVID-19 vaccine is urgently needed to prevent the disease, thwart the complications and avert deaths resulting from unrestrained transmission of the infection. The hubris: Vaccine development: While most of the platforms of vaccine candidates have focused on the spike (S) protein and its variants as the primary antigen of COVID-19 infection, various techniques involved include nucleic acid technologies (RNA and DNA), non-replicating viral vectors, peptides, recombinant proteins, live attenuated and inactivated viruses. There are novel vaccine technologies being developed using next-generation strategies for precision and flexibility for antigen manipulation relating to SARS-CoV-2 infection mechanisms. The elpis: Updates and prospects: There were nine different technology platforms under research and development to create an effective vaccine against COVID 19. Although there are no licensed vaccines against COVID-19 yet, there are various potential vaccine candidates under development and advanced clinical trials. Out of them, one having undergone phase III clinical trials, has become available in some countries for use among the high-risk groups following emergency use authorization. Other COVID-19 vaccines may soon follow the suit. Conclusion: Hopes and concerns: The hope of benefiting from the vaccine to the extent that it may be the only way to tide over and control the COVID-19 pandemic, is accompanied by the likely fear of adverse effects and opposition in public for COVID-19 vaccination, including the vaccine hesitancy. Further, there is concern among scientific circles that vaccine may have opposite of the desired effect by causing antibody-dependent disease enhancement.

scholarly journals Viral Vectors for COVID-19 Vaccine Development

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 317
Author(s):  
Kenneth Lundstrom
Keyword(s):  
Immune Responses ◽  
Viral Vectors ◽  
Vaccine Development ◽  
Rna Virus ◽  
Influenza Viruses ◽  
Spike Protein ◽  
Vaccine Candidates ◽  
Vaccinia Viruses ◽  
Simian Adenovirus ◽  
The Uk

Vaccine development against SARS-CoV-2 has been fierce due to the devastating COVID-19 pandemic and has included all potential approaches for providing the global community with safe and efficient vaccine candidates in the shortest possible timeframe. Viral vectors have played a central role especially using adenovirus-based vectors. Additionally, other viral vectors based on vaccinia viruses, measles viruses, rhabdoviruses, influenza viruses and lentiviruses have been subjected to vaccine development. Self-amplifying RNA virus vectors have been utilized for lipid nanoparticle-based delivery of RNA as COVID-19 vaccines. Several adenovirus-based vaccine candidates have elicited strong immune responses in immunized animals and protection against challenges in mice and primates has been achieved. Moreover, adenovirus-based vaccine candidates have been subjected to phase I to III clinical trials. Recently, the simian adenovirus-based ChAdOx1 vector expressing the SARS-CoV-2 S spike protein was approved for use in humans in the UK.

scholarly journals Viral vector-based vaccines against SARS-CoV-2

2021 ◽  
pp. 295-308
Author(s):  
Kenneth Lundstrom
Keyword(s):  
Clinical Trials ◽  
Vaccine Efficacy ◽  
Measles Virus ◽  
Viral Vectors ◽  
Vaccine Development ◽  
Viral Vector ◽  
Adenovirus Vector ◽  
Influenza Viruses ◽  
Vaccine Candidates ◽  
Lentivirus Vectors

Viral vectors have been frequently applied for vaccine development. It has also been the case for vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to tackle the coronavirus disease 2019 (COVID-19) pandemic. A multitude of different viral vectors have been mainly targeting the SARS-CoV-2 spike (S) protein as antigen. Intramuscular injection has been most commonly used, but also intranasal administration has been tested. Adenovirus vector-based vaccines are the most advanced with several vaccines receiving Emergency Use Authorization (EUA). The simian ChAdOx1 nCoV-19 vaccine applied as a prime-boost regimen has provided 62.1–90% vaccine efficacy in clinical trials. The Ad26.COV2.S vaccine requires only one immunization to provide protection against SARS-CoV-2. The rAd26-S/rAd5-S vaccine utilizes the Ad26 serotype for the prime immunization followed by a boost with the Ad5 serotype resulting in 91.2% vaccine efficacy. All adenovirus-based vaccines are used for mass vaccinations. Moreover, vaccine candidates based on vaccinia virus and lentivirus vectors have been subjected to clinical evaluation. Among self-replicating RNA viruses, vaccine vectors based on measles virus, rhabdoviruses, and alphaviruses have been engineered and tested in clinical trials. In addition to the intramuscular route of administration vaccine candidates based on influenza viruses and adenoviruses have been subjected to intranasal delivery showing antibody responses and protection against SARS-CoV-2 challenges in animal models. The detection of novel more transmissible and pathogenic SARS-CoV-2 variants added concerns about the vaccine efficacy and needs to be monitored. Moreover, the cause of recently documented rare cases of vaccine-induced immune thrombotic thrombocytopenia (VITT) must be investigated.

A multi-method and structure-based in silico vaccine designing against Helicobacter pylori employing immuno-informatics approach

2020 ◽  
Vol 17 ◽  
Author(s):  
Anam Naz ◽  
Tahreem Zaheer ◽  
Hamza Arshad Dar ◽  
Faryal Mehwish Awan ◽  
Ayesha Obaid ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Vaccine Development ◽  
Amino Acid Sequences ◽  
The Body ◽  
New Drugs ◽  
Toll Like Receptor ◽  
Peptide Vaccines ◽  
Hla Alleles ◽  
Vaccine Candidates ◽  
H Pylori

Background: Helicobacter pylori infection and its treatment still remains a challenge to human health worldwide. A variety of antibiotics and combination therapies are currently used to treat H. pylori induced ulcers and carcinoma; however, no effective treatment is available to eliminate the pathogen from the body. Additionally, antibiotic resistance is also one of the main reasons for prolonged and persistent infection. Aim of the study: Until new drugs are available for this infection, vaccinology seems the only alternative opportunity to exploit against H. pylori induced diseases. Methods: Multiple epitopes prioritized in our previous study have been tested for their possible antigenic combinations, and results in 169-mer and 183-mer peptide vaccines containing the amino acid sequences of 3 and 4 epitopes respectively, along with adjuvant (Cholera Toxin Subunit B adjuvant at 5’ end) and linkers (GPGPG and EAAAK). Results: Poly-epitope proteins proposed as potential vaccine candidates against H. pylori include SabAHP0289-Omp16-VacA (SHOV), VacA-Omp16-HP0289-FecA (VOHF), VacA-Omp16-HP0289-SabA (VOHS), VacA-Omp16-HP0289-BabA (VOHB), VacA-Omp16-HP0289-SabA-FecA (VOHSF), VacAOmp16-HP0289-SabA-BabA (VOHSB) and VacA-Omp16-HP0289-BabA-SabA (VOHBS). Structures of these poly-epitope peptide vaccines have been modelled and checked for their affinity with HLA alleles and receptors. These proposed poly-epitope vaccine candidates bind efficiently with A2, A3, B7 and DR1 superfamilies of HLA alleles. They can also form stable and significant interactions with Toll-like receptor 2 and Toll-like receptor 4. Conclusion: Results suggest that these multi-epitopic vaccines can elicit a significant immune response against H. pylori and can be tested further for efficient vaccine development.

scholarly journals Strategies for Vaccination: Conventional Vaccine Approaches Versus New-Generation Strategies in Combination with Adjuvants

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 140
Author(s):  
Abdellatif Bouazzaoui ◽  
Ahmed A. H. Abdellatif ◽  
Faisal A. Al-Allaf ◽  
Neda M. Bogari ◽  
Saied Al-Dehlawi ◽  
...  
Keyword(s):  
Viral Vectors ◽  
Protein Production ◽  
Vaccine Development ◽  
Effective Vaccine ◽  
The Novel ◽  
Research Teams ◽  
Advantages And Disadvantages ◽  
Rapid Spread ◽  
New Generation ◽  
Conventional Vaccine

The current COVID-19 pandemic, caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), has raised significant economic, social, and psychological concerns. The rapid spread of the virus, coupled with the absence of vaccines and antiviral treatments for SARS-CoV-2, has galvanized a major global endeavor to develop effective vaccines. Within a matter of just a few months of the initial outbreak, research teams worldwide, adopting a range of different strategies, embarked on a quest to develop effective vaccine that could be effectively used to suppress this virulent pathogen. In this review, we describe conventional approaches to vaccine development, including strategies employing proteins, peptides, and attenuated or inactivated pathogens in combination with adjuvants (including genetic adjuvants). We also present details of the novel strategies that were adopted by different research groups to successfully transfer recombinantly expressed antigens while using viral vectors (adenoviral and retroviral) and non-viral delivery systems, and how recently developed methods have been applied in order to produce vaccines that are based on mRNA, self-amplifying RNA (saRNA), and trans-amplifying RNA (taRNA). Moreover, we discuss the methods that are being used to enhance mRNA stability and protein production, the advantages and disadvantages of different methods, and the challenges that are encountered during the development of effective vaccines.

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