scholarly journals A Whole Virion Vaccine for COVID-19 Produced via a Novel Inactivation Method and Preliminary Demonstration of Efficacy in an Animal Challenge Model

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 340
Author(s):  
Izabela K Ragan ◽  
Lindsay M Hartson ◽  
Taru S Dutt ◽  
Andres Obregon-Henao ◽  
Rachel M Maison ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Rapid Development ◽  
Neutralizing Antibody ◽  
Emerging Diseases ◽  
Effective Vaccine ◽  
Preliminary Evaluation ◽  
Sequencing Data ◽  
Post Challenge ◽  
Vaccine Candidates ◽  
The Impact

The COVID-19 pandemic has generated intense interest in the rapid development and evaluation of vaccine candidates for this disease and other emerging diseases. Several novel methods for preparing vaccine candidates are currently undergoing clinical evaluation in response to the urgent need to prevent the spread of COVID-19. In many cases, these methods rely on new approaches for vaccine production and immune stimulation. We report on the use of a novel method (SolaVAX) for production of an inactivated vaccine candidate and the testing of that candidate in a hamster animal model for its ability to prevent infection upon challenge with SARS-CoV-2 virus. The studies employed in this work included an evaluation of the levels of neutralizing antibody produced post-vaccination, levels of specific antibody sub-types to RBD and spike protein that were generated, evaluation of viral shedding post-challenge, flow cytometric and single cell sequencing data on cellular fractions and histopathological evaluation of tissues post-challenge. The results from this preliminary evaluation provide insight into the immunological responses occurring as a result of vaccination with the proposed vaccine candidate and the impact that adjuvant formulations, specifically developed to promote Th1 type immune responses, have on vaccine efficacy and protection against infection following challenge with live SARS-CoV-2. This data may have utility in the development of effective vaccine candidates broadly. Furthermore, the results of this preliminary evaluation suggest that preparation of a whole virion vaccine for COVID-19 using this specific photochemical method may have potential utility in the preparation of one such vaccine candidate.

scholarly journals A whole virion vaccine for COVID-19 produced via a novel inactivation method: results from animal challenge model studies

2020 ◽  
Author(s):  
Izabela K Ragan ◽  
Lindsay M Hartson ◽  
Taru S Dutt ◽  
Andres Obregon-Henao ◽  
Rachel M Maison ◽  
...  
Keyword(s):  
Animal Model ◽  
Vaccine Candidate ◽  
Rapid Development ◽  
Emerging Diseases ◽  
Effective Vaccine ◽  
Sequencing Data ◽  
Post Challenge ◽  
Vaccine Candidates ◽  
Novel Method ◽  
The Impact

AbstractThe COVID-19 pandemic has generated intense interest in the rapid development and evaluation of vaccine candidates for this disease and other emerging diseases. Several novel methods for preparing vaccine candidates are currently undergoing clinical evaluation in response to the urgent need to prevent the spread of COVID-19. In many cases, these methods rely on new approaches for vaccine production and immune stimulation. We report on the use of a novel method (SolaVAX™) for production of an inactivated vaccine candidate and the testing of that candidate in a hamster animal model for its ability to prevent infection upon challenge with SARS-CoV-2 virus. The studies employed in this work included an evaluation of the levels of neutralizing antibody produced post-vaccination, levels of specific antibody sub-types to RBD and spike protein that were generated, evaluation of viral shedding post-challenge, flow cytometric and single cell sequencing data on cellular fractions and histopathological evaluation of tissues post-challenge. The results from this study provide insight into the immunological responses occurring as a result of vaccination with the proposed vaccine candidate and the impact that adjuvant formulations, specifically developed to promote Th1 type immune responses, have on vaccine efficacy and protection against infection following challenge with live SARS-CoV-2. This data may have utility in the development of effective vaccine candidates broadly. Furthermore, the results suggest that preparation of a whole virion vaccine for COVID-19 using this specific photochemical method may have utility in the preparation of one such vaccine candidate.Author SummaryWe have developed a vaccine for COVID-19 which is prepared by a novel method for inactivation of a whole virion particle and tested it in a hamster animal model for its ability to protect against SARS-CoV-2 infection.

scholarly journals Immunization with RBD-P2 and N protects against SARS-CoV-2 in nonhuman primates

2021 ◽  
Vol 7 (22) ◽  
pp. eabg7156
Author(s):  
So-Hee Hong ◽  
Hanseul Oh ◽  
Yong Wook Park ◽  
Hye Won Kwak ◽  
Eun Young Oh ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Nonhuman Primates ◽  
Vaccine Candidate ◽  
Statistical Significance ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Vaccine Candidates ◽  
Cell Responses ◽  
Antibody Levels ◽  
Further Development

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.

scholarly journals Rapid development of SARS-CoV-2 receptor binding domain-conjugated nanoparticle vaccine candidate

2020 ◽  
Author(s):  
Yin-Feng Kang ◽  
Cong Sun ◽  
Zhen Zhuang ◽  
Run-Yu Yuan ◽  
Qing-Bing Zheng ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Vaccine Development ◽  
Vaccine Candidate ◽  
Rapid Development ◽  
Scale Up ◽  
Physical Stability ◽  
Covalent Bond ◽  
Neutralizing Antibody ◽  
Economic Losses

AbstractThe ongoing of coronavirus disease 2019 (COVID-19) pandemic caused by novel SARS-CoV-2 coronavirus, resulting in economic losses and seriously threating the human health in worldwide, highlighting the urgent need of a stabilized, easily produced and effective preventive vaccine. The SARS-COV-2 spike protein receptor binding region (RBD) plays an important role in the process of viral binding receptor angiotensin-converting enzyme 2 (ACE2) and membrane fusion, making it an ideal target for vaccine development. In this study, we designed three different RBD-conjugated nanoparticles vaccine candidates, RBD-Ferritin (24-mer), RBD-mi3 (60-mer) and RBD-I53-50 (120-mer), with the application of covalent bond linking by SpyTag-SpyCatcher system. It was demonstrated that the neutralizing capability of sera from mice immunized with three RBD-conjugated nanoparticles adjuvanted with AddaVax or Sigma Systerm Adjuvant (SAS) after each immunization was ~8-to 120-fold greater than monomeric RBD group in SARS-CoV-2 pseudovirus and authentic virus neutralization assay. Most importantly, sera from RBD-conjugated NPs groups more efficiently blocked the binding of RBD to ACE2 or neutralizing antibody in vitro, a further proof of promising immunization effect. Besides, high physical stability and flexibility in assembly consolidated the benefit for rapid scale-up production of vaccine. These results supported that our designed SARS-CoV-2 RBD-conjugated nanoparticle was competitive vaccine candidate and the carrier nanoparticles could be adopted as universal platform for future vaccine development.

scholarly journals Global distribution of single amino acid polymorphisms in Plasmodium vivax Duffy-binding-like domain and implications for vaccine development efforts

Open Biology ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 200180
Author(s):  
Payal Mittal ◽  
Siddhartha Mishra ◽  
Sonalika Kar ◽  
Veena Pande ◽  
Abhinav Sinha ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Binding Sites ◽  
Vaccine Development ◽  
Vaccine Candidate ◽  
Neutralizing Antibody ◽  
Single Amino Acid ◽  
Vaccine Candidates ◽  
Malaria Burden ◽  
Single Amino Acid Polymorphisms ◽  
Polymorphic Residue

Plasmodium vivax ( Pv ) malaria continues to be geographically widespread with approximately 15 million worldwide cases annually. Along with other proteins, Duffy-binding proteins (DBPs) are used by plasmodium for RBC invasion and the parasite-encoded receptor binding regions lie in their Duffy-binding-like (DBL) domains—thus making it a prime vaccine candidate. This study explores the sequence diversity in Pv DBL globally, with an emphasis on India as it remains a major contributor to the global Pv malaria burden. Based on 1358 Pv DBL protein sequences available in NCBI, we identified 140 polymorphic sites within 315 residues of Pv DBL. Alarmingly, country-wise mapping of SAAPs from field isolates revealed varied and distinct polymorphic profiles for different nations. We report here 31 polymorphic residue positions in the global SAAP profile, most of which map to the Pv DBL subdomain 2 ( α 1– α 6). A distinct clustering of SAAPs distal to the DARC-binding sites is indicative of immune evasive strategies by the parasite. Analyses of Pv DBL-neutralizing antibody complexes revealed that between 24% and 54% of interface residues are polymorphic. This work provides a framework to recce and expand the polymorphic space coverage in Pv DBLs as this has direct implications for vaccine development studies. It also emphasizes the significance of surveying global SAAP distributions before or alongside the identification of vaccine candidates.

scholarly journals A SARS-CoV-2 vaccine candidate would likely match all currently circulating strains

2020 ◽  
Author(s):  
Bethany Dearlove ◽  
Eric Lewitus ◽  
Hongjun Bai ◽  
Yifan Li ◽  
Daniel B. Reeves ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Sequence Diversity ◽  
Spike Protein ◽  
Effective Vaccine ◽  
Virus Spread ◽  
Vaccine Candidates ◽  
Human Host

AbstractThe magnitude of the COVID-19 pandemic underscores the urgency for a safe and effective vaccine. Here we analyzed SARS-CoV-2 sequence diversity across 5,700 sequences sampled since December 2019. The Spike protein, which is the target immunogen of most vaccine candidates, showed 93 sites with shared polymorphisms; only one of these mutations was found in more than 1% of currently circulating sequences. The minimal diversity found among SARS-CoV-2 sequences can be explained by drift and bottleneck events as the virus spread away from its original epicenter in Wuhan, China. Importantly, there is little evidence that the virus has adapted to its human host since December 2019. Our findings suggest that a single vaccine should be efficacious against current global strains.One Sentence SummaryThe limited diversification of SARS-CoV-2 reflects drift and bottleneck events rather than adaptation to humans as the virus spread.

scholarly journals A Rational Design of a Multi-Epitope Vaccine Against SARS-CoV-2 Which Accounts for the Glycan Shield of the Spike Glycoprotein

2020 ◽  
Author(s):  
William R. Martin ◽  
Feixiong Cheng
Keyword(s):  
T Lymphocytes ◽  
B Lymphocytes ◽  
Rational Design ◽  
Vaccine Candidate ◽  
Rapid Development ◽  
Spike Glycoprotein ◽  
Epitope Vaccine ◽  
Effective Prevention ◽  
Health Crisis ◽  
Vaccine Candidates

<p>The ongoing global health crisis caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus which leads to Coronavirus Disease 2019 (COVID-19) has impacted not only the health of people everywhere, but the economy in nations across the world. While vaccine candidates and therapeutics are currently undergoing clinical trials, there is yet to be a proven effective treatment or cure for COVID-19. In this study, we have presented a synergistic computational platform, including molecular dynamics simulations and immunoinformatics techniques, to rationally design a multi-epitope vaccine candidate for COVID-19. This platform combines epitopes across Linear B Lymphocytes (LBL), Cytotoxic T Lymphocytes (CTL) and Helper T Lymphocytes (HTL) derived from both mutant and wild-type spike glycoproteins from SARS-CoV-2 with diverse protein conformations. In addition, this vaccine construct also takes the considerable glycan shield of the spike glycoprotein into account, which protects it from immune response. We have identified a vaccine candidate (a 35.9 kDa protein), named COVCCF, which is composed of 5 LBL, 6 HTL, and 6 CTL epitopes from the spike glycoprotein of SARS-CoV-2. Using multi-dose immune simulations, COVCCF induces elevated levels of immunoglobulin activity (IgM, IgG1, IgG2), and induces strong responses from B lymphocytes, CD4 T-helper lymphocytes, and CD8 T-cytotoxic lymphocytes. COVCCF induces cytokines important to innate immunity, including IFN-γ, IL4, and IL10. Additionally, COVCCF has ideal pharmacokinetic properties and low immune-related toxicities. In summary, this study provides a powerful, computational vaccine design platform for rapid development of vaccine candidates (including COVCCF) for effective prevention of COVID-19.</p>

scholarly journals Development of a potent Zika virus vaccine using self-amplifying messenger RNA

2020 ◽  
Vol 6 (32) ◽  
pp. eaba5068 ◽  
Author(s):  
Kate Luisi ◽  
Kaitlyn M. Morabito ◽  
Katherine E. Burgomaster ◽  
Mayuri Sharma ◽  
Wing-Pui Kong ◽  
...  
Keyword(s):  
Zika Virus ◽  
Messenger Rna ◽  
Protective Immunity ◽  
Nonhuman Primates ◽  
Neutralizing Antibody ◽  
Effective Vaccine ◽  
Proof Of Concept ◽  
Zikv Infection ◽  
Vaccine Candidates ◽  
Rapid Responses

Zika virus (ZIKV) is the cause of a pandemic associated with microcephaly in newborns and Guillain-Barre syndrome in adults. Currently, there are no available treatments or vaccines for ZIKV, and the development of a safe and effective vaccine is a high priority for many global health organizations. We describe the development of ZIKV vaccine candidates using the self-amplifying messenger RNA (SAM) platform technology delivered by cationic nanoemulsion (CNE) that allows bedside mixing and is particularly useful for rapid responses to pandemic outbreaks. Two immunizations of either of the two lead SAM (CNE) vaccine candidates elicited potent neutralizing antibody responses to ZIKV in mice and nonhuman primates. Both SAM (CNE) vaccines protected these animals from ZIKV challenge, with one candidate providing complete protection against ZIKV infection in nonhuman primates. The data provide a preclinical proof of concept that a SAM (CNE) vaccine candidate can rapidly elicit protective immunity against ZIKV.

scholarly journals Immunogenicity of Adjuvanted Psoralen-Inactivated SARS-CoV-2 Vaccines and SARS-CoV-2 Spike Protein DNA Vaccines in BALB/c Mice

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 626
Author(s):  
Appavu K. Sundaram ◽  
Daniel Ewing ◽  
Zhaodong Liang ◽  
Vihasi Jani ◽  
Ying Cheng ◽  
...  
Keyword(s):  
Dna Vaccines ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Effective Vaccine ◽  
Inactivated Vaccine ◽  
Vaccine Candidates ◽  
Global Priority ◽  
Clinical Stages ◽  
Dose Dependent ◽  
Type Response

The development of a safe and effective vaccine to protect against COVID-19 is a global priority due to the current high SARS-CoV-2 infection rate. Currently, there are over 160 SARS-CoV-2 vaccine candidates at the clinical or pre-clinical stages of development. Of these, there are only three whole-virus vaccine candidates produced using β-propiolactone or formalin inactivation. Here, we prepared a whole-virus SARS-CoV-2 vaccine (SARS-CoV-2 PsIV) using a novel psoralen inactivation method and evaluated its immunogenicity in mice using two different adjuvants, alum and Advax-2. We compared the immunogenicity of SARS-CoV-2 PsIV against SARS-CoV-2 DNA vaccines expressing either full-length or truncated spike proteins. We also compared the psoralen-inactivated vaccine against a DNA prime, psoralen-inactivated vaccine boost regimen. After two doses, the psoralen-inactivated vaccine, when administered with alum or Advax-2 adjuvants, generated a dose-dependent neutralizing antibody responses in mice. Overall, the pattern of cytokine ELISPOT responses to antigen-stimulation observed in this study indicates that SARS-CoV-2 PsIV with the alum adjuvant promotes a Th2-type response, while SARS-CoV-2 PsIV with the Advax-2 adjuvant promotes a Th1-type response.

scholarly journals Single-component, self-assembling, protein nanoparticles presenting the receptor binding domain and stabilized spike as SARS-CoV-2 vaccine candidates

2021 ◽  
Vol 7 (12) ◽  
pp. eabf1591
Author(s):  
Linling He ◽  
Xiaohe Lin ◽  
Ying Wang ◽  
Ciril Abraham ◽  
Cindy Sou ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Vaccine Candidate ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Heptad Repeat ◽  
Receptor Binding Domain ◽  
Vaccine Candidates ◽  
Self Assembling ◽  
Cell Immunity ◽  
Promising Vaccine Candidate

Vaccination against SARS-CoV-2 provides an effective tool to combat the COVID-19 pandemic. Here, we combined antigen optimization and nanoparticle display to develop vaccine candidates for SARS-CoV-2. We first displayed the receptor-binding domain (RBD) on three self-assembling protein nanoparticle (SApNP) platforms using the SpyTag/SpyCatcher system. We then identified heptad repeat 2 (HR2) in S2 as the cause of spike metastability, designed an HR2-deleted glycine-capped spike (S2GΔHR2), and displayed S2GΔHR2 on SApNPs. An antibody column specific for the RBD enabled tag-free vaccine purification. In mice, the 24-meric RBD-ferritin SApNP elicited a more potent neutralizing antibody (NAb) response than the RBD alone and the spike with two stabilizing proline mutations in S2 (S2P). S2GΔHR2 elicited twofold higher NAb titers than S2P, while S2GΔHR2 SApNPs derived from multilayered E2p and I3-01v9 60-mers elicited up to 10-fold higher NAb titers. The S2GΔHR2-presenting I3-01v9 SApNP also induced critically needed T cell immunity, thereby providing a promising vaccine candidate.

scholarly journals A Review of the Animal and Human Trials of the Ad5-nCoV Vaccine Candidate

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Cheng En Xi ◽  
Jasrita Singh
Keyword(s):  
Immune Response ◽  
Vaccine Candidate ◽  
Recombinant Adenovirus ◽  
Neutralizing Antibody ◽  
Effective Vaccine ◽  
Strong Immune Response ◽  
Human Trials ◽  
Search Terms ◽  
Global Pandemic ◽  
Pubmed Database

Since the COVID-19 outbreak began, there has been an urgent need for a safe and effective vaccine to end this global pandemic. One such vaccine is the Ad5-nCoV, developed by CanSino Biologics Inc. This review aims to examine all animal and human trials conducted for this vaccine candidate. Search terms such as “Ad5-nCoV”, “recombinant adenovirus”, “COVID-19”, and “vaccine”, were used in varying combinations in the PubMed database to find published trial reports. It was concluded that Ad5-nCoV can induce a strong immune response in mice and ferret models and offer them protection against the inoculation of SARS-CoV-2. It also has a strong safety profile in human and can induce an adequate immune response in terms of RBD-specific antibodies and T cell responses, while neutralizing antibody response and seroconversion was mediocre. The publish trial reports support the further testing of this vaccine candidate and it is preparing to enter phase 3 clinical trials.

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