scholarly journals Design and Immunological Properties of the Novel Subunit Virus-like Vaccine against SARS-CoV-2

Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 69
Author(s):  
Igor V. Krasilnikov ◽  
Aleksandr V. Kudriavtsev ◽  
Anna V. Vakhrusheva ◽  
Maria E. Frolova ◽  
Aleksandr V. Ivanov ◽  
...  

The COVID-19 pandemic is ongoing, and the need for safe and effective vaccines to prevent infection and to control spread of the virus remains urgent. Here, we report the development of a SARS-CoV-2 subunit vaccine candidate (Betuvax-CoV-2) based on RBD and SD1 domains of the spike (S) protein fused to a human IgG1 Fc fragment. The antigen is adsorbed on betulin adjuvant, forming spherical particles with a size of 100–180 nm, mimicking the size of viral particles. Here we confirm the potent immunostimulatory activity of betulin adjuvant, and demonstrate that two immunizations of mice with Betuvax-CoV-2 elicited high titers of RBD-specific antibodies. The candidate vaccine was also effective in stimulating a neutralizing antibody response and T cell immunity. The results indicate that Betuvax-CoV-2 has good potential for further development as an effective vaccine against SARS-CoV-2.

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1936
Author(s):  
Yi-Sheng Sun ◽  
Jing-Jing Zhou ◽  
Han-Ping Zhu ◽  
Fang Xu ◽  
Wen-Bin Zhao ◽  
...  

The novel coronavirus pneumonia (COVID-19) pandemic is a great threat to human society and now is still spreading. Although several vaccines have been authorized for emergency use, only one recombinant subunit vaccine has been permitted for widespread use. More subunit vaccines for COVID-19 should be developed in the future. The receptor binding domain (RBD), located at the S protein of SARS-CoV-2, contains most of the neutralizing epitopes. However, the immunogenicity of RBD monomers is not strong enough. In this study, we fused the RBD-monomer with a modified Fc fragment of human IgG1 to form an RBD-Fc fusion protein. The recombinant vaccine candidate based on the RBD-Fc protein could induce high levels of IgG and neutralizing antibody in mice, and these could last for at least three months. The secretion of IFN-γ, IL-2 and IL-10 in the RBD-stimulated splenocytes of immunized mice also increased significantly. Our results first showed that the RBD-Fc vaccine could induce both humoral and cellular immune responses and might be an optional strategy to control COVID-19.


2005 ◽  
Vol 202 (9) ◽  
pp. 1179-1184 ◽  
Author(s):  
Giovanna Barba-Spaeth ◽  
Randy S. Longman ◽  
Matthew L. Albert ◽  
Charles M. Rice

The yellow fever (YF) 17D vaccine is one of the most successful live attenuated vaccines available. A single immunization induces both long-lasting neutralizing antibody and YF-specific T cell responses. Surprisingly, the mechanism for this robust immunity has not been addressed. In light of several recent reports suggesting flavivirus interaction with dendritic cells (DCs), we investigated the mechanism of YF17D interaction with DCs and the importance of this interaction in generating T cell immunity. Our results show that YF17D can infect immature and mature human DCs. Viral entry is Ca2+ dependent, but it is independent of DC-SIGN as well as multiple integrins expressed on the DC surface. Similar to infection of cell lines, YF infection of immature DCs is cytopathic. Although infection itself does not induce DC maturation in vitro, TNF-α–induced maturation protects DCs from YF-induced cytopathogenicity. Furthermore, we show that DCs infected with YF17D or YF17D carrying a recombinant epitope can process and present antigens for CD8+ T cell stimulation. These findings offer insight into the immunologic mechanisms associated with the highly capable YF17D vaccine that may guide effective vaccine design.


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 ◽  
...  

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.


Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 340
Author(s):  
Izabela K Ragan ◽  
Lindsay M Hartson ◽  
Taru S Dutt ◽  
Andres Obregon-Henao ◽  
Rachel M Maison ◽  
...  

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.


2021 ◽  
Vol 7 (22) ◽  
pp. eabg7156
Author(s):  
So-Hee Hong ◽  
Hanseul Oh ◽  
Yong Wook Park ◽  
Hye Won Kwak ◽  
Eun Young Oh ◽  
...  

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.


2021 ◽  
Vol 14 (3) ◽  
pp. 265
Author(s):  
Ana Dolšak ◽  
Tomaž Bratkovič ◽  
Larisa Mlinarič ◽  
Eva Ogorevc ◽  
Urban Švajger ◽  
...  

Indoleamine 2,3-dioxygenase 1 (IDO1) is a promising target in immunomodulation of several pathological conditions, especially cancers. Here we present the synthesis of a series of IDO1 inhibitors with the novel isoxazolo[5,4-d]pyrimidin-4(5H)-one scaffold. A focused library was prepared using a 6- or 7-step synthetic procedure to allow a systematic investigation of the structure-activity relationships of the described scaffold. Chemistry-driven modifications lead us to the discovery of our best-in-class inhibitors possessing p-trifluoromethyl (23), p-cyclohexyl (32), or p-methoxycarbonyl (20, 39) substituted aniline moieties with IC50 values in the low micromolar range. In addition to hIDO1, compounds were tested for their inhibition of indoleamine 2,3-dioxygenase 2 and tryptophan dioxygenase, and found to be selective for hIDO1. Our results thus demonstrate a successful study on IDO1-selective isoxazolo[5,4-d]pyrimidin-4(5H)-one inhibitors, defining promising chemical probes with a novel scaffold for further development of potent small-molecule immunomodulators.


2021 ◽  
Author(s):  
Qingyu Zhao ◽  
Yanan Gao ◽  
Min Xiao ◽  
Xuefei Huang ◽  
Xuanjun Wu

For prevention of the coronavirus disease 2019 caused by the novel coronavirus SARS-CoV-2, an effective vaccine is critical. Herein, several potential peptide epitopes from the spike protein of SARS-CoV-2 have...


Author(s):  
Anurag Singh ◽  
Anand Maurya ◽  
Gaurav Mishra ◽  
Rajendra Awasthi ◽  
Kamal Dua ◽  
...  

Background: The novel coronavirus 2019 (COVID-19) infection has caused the global emergence of coronavirus in humans during the last 12 months. Till May 11, 2021, the confirmed global COVID-19 cases and deaths reached 158551526 and 3296855, respectively. Methods: Goblet cells and ciliated cells in the nose act as the initial infection site of SARS-CoV-2. Thus, mucus immunity is important to protect from infection. The outburst of SARS-CoV-2 infection can be halted only when an effective vaccine will be developed. Results: Globally, over 100 different vaccines are under investigation, including DNA vaccines, RNA vaccines, inactivated virus vaccines, adenovirus-based vaccines, recombinant/ subunit protein vaccines, peptide vaccines, and virus-like particles etc. Inactivated virus vaccines and mRNA, and adenovirus-based vaccines have moved fast into clinical trials. Conclusion: : Vaccines containing spike protein of SARS-CoV as subunit could effectively prevent binding of coronavirus to the host cell and membrane fusion. Thus, spike protein can be used as a major target for subunit vaccine preparation.


2021 ◽  
Author(s):  
Hongbo Liu ◽  
Xiang Gao ◽  
Guoyong Wang ◽  
Jianjun Zhang ◽  
Jiajie Zhou ◽  
...  

The COVID-19 pandemic and the continued spreading of the SARS-CoV-2 variants have brought a grave public health consequence and severely devastated the global economy with recessions. Vaccination is considered as one of the most promising and efficient methods to end the COVID-19 pandemic and mitigate the disease conditions if infected. Although a few vaccines have been developed with an unprecedented speed, scientists around the world are continuing pursuing the best possible vaccines with innovations. Comparing to the expensive mRNA vaccines and attenuated/inactivated SARS-CoV-2 vaccines, recombinant protein vaccines have certain advantages, including their safety (non-virus components), potential stronger immunogenicity, broader protection, ease of scaling-up production, reduced cost, etc. In this study, we reported a novel COVID-19 vaccine generated with RBD-HR1/HR2 hexamer that was creatively fused with the RBD domain and heptad repeat 1 (HR1) or heptad repeat 2 (HR2) to form a dumbbell-shaped hexamer to target the spike S1 subunit. The novel hexamer COVID-19 vaccine induced high titers of neutralizing antibody in mouse studies (>100,000), and further experiments also showed that the vaccine also induced an alternative antibody to the HR1 region, which probably alleviated the drop of immunogenicity from the frequent mutations of SARS-CoV-2.


Author(s):  
Manal M.E. Ahmed ◽  
Jakeen Eljakee ◽  
Tarek Mahran

Pseudomonas aeruginosa is an opportunistic pathogen affecting immuno-compromised patients; however, no effective vaccine is currently available in the market. Here, we developed novel polyvalent irradiated P. aeruginosa vaccine using cobalt 60 that inhibited pathogen viability but retained antigenic expression functionally. Mice were vaccinated by the developed vaccine by intranasal, intramuscular and subcutaneous route of administration followed by challenge test. The protective efficacy of the novel vaccine reached up to 95%. This significant protection was mainly associated with measurable antiserum opsonic killing activity. In conclusion, the novel vaccine provides a promising strategy of both prophylactic and therapeutic approaches for immuno-compromised patients against MDR P. aeruginosa.


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