scholarly journals Advances in the design and development of SARS-CoV-2 vaccines

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xue-Liang Peng ◽  
Ji-Si-Yu Cheng ◽  
Hai-Lun Gong ◽  
Meng-Di Yuan ◽  
Xiao-Hong Zhao ◽  
...  

AbstractSince the end of 2019, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The RNA genome of SARS-CoV-2, which is highly infectious and prone to rapid mutation, encodes both structural and nonstructural proteins. Vaccination is currently the only effective method to prevent COVID-19, and structural proteins are critical targets for vaccine development. Currently, many vaccines are in clinical trials or are already on the market. This review highlights ongoing advances in the design of prophylactic or therapeutic vaccines against COVID-19, including viral vector vaccines, DNA vaccines, RNA vaccines, live-attenuated vaccines, inactivated virus vaccines, recombinant protein vaccines and bionic nanoparticle vaccines. In addition to traditional inactivated virus vaccines, some novel vaccines based on viral vectors, nanoscience and synthetic biology also play important roles in combating COVID-19. However, many challenges persist in ongoing clinical trials.

2014 ◽  
Vol 3 (1) ◽  
pp. 10 ◽  
Author(s):  
Yongneng Luo ◽  
Limin Jiang ◽  
Zi'an Mao

<p>  Hepatitis C virus infects nearly 3% of the global population, and spreads to 3-4 million new people annually. HCV infection is a leading cause of liver cirrhosis, hepatocellular carcinoma, and end-stage liver diseases and causes liver-related death in more than 300,000 people each year. Unfortunately, there is currently no vaccine for HCV prevention (prophylactic vaccine) or treatment (therapeutic vaccine). Circulating HCV is genetically diverse, and therefore a broadly effective vaccine must target conserved T- and B-cell epitopes of the virus and induce strong cross-reactive CD4+/CD8+ T-cell and neutralizing antibody responses in preventing or clearing HCV infection. So far, a few of vaccine development approaches are successful and some of the HCV vaccine candidates have reached human clinical trials, including those modalities mainly based on recombinant proteins (envelope proteins and core protein subunit), synthetic peptides, DNA (plasmid) and viral vectors (virosome). Encouraging results were obtained for those HCV vaccine formulations consisting of prime-boost regimen involving a live recombinant viral vector vaccine alone or in combination with DNA or subunit vaccine. Among several other vaccine strategies under preclinical development, the most promising one is virus like particle based vaccine that will be moving into human studies soon.</p>


2021 ◽  
pp. 295-308
Author(s):  
Kenneth Lundstrom

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.


Author(s):  
Zuzana Strizova ◽  
Jitka Smetanova ◽  
Jirina Bartunkova ◽  
Tomas Milota

The number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients keeps rising in most of the European countries despite the pandemic precaution measures. The current antiviral and anti-inflammatory therapeutic approaches are only supportive, have limited efficacy, and the prevention in reducing the transmission of SARS-CoV-2 virus is the best hope for public health. It is presumed that an effective vaccination against SARS-CoV-2 infection could mobilize the innate and adaptive immune responses and provide a protection against severe forms of coronavirus disease 2019 (COVID-19) disease. As the race for the effective and safe vaccine has begun, different strategies were introduced. To date, viral vector-based vaccines, genetic vaccines, attenuated vaccines, and protein-based vaccines are the major vaccine types tested in the clinical trials. Over 80 clinical trials have been initiated; however, only 18 vaccines have reached the clinical phase II/III or III, and 4 vaccine candidates are under consideration or have been approved for the use so far. In addition, the protective effect of the off-target vaccines, such as <i>Bacillus</i> Calmette-Guérin and measles vaccine, is being explored in randomized prospective clinical trials with SARS-CoV-2-infected patients. In this review, we discuss the most promising anti-COVID-19 vaccine clinical trials and different vaccination strategies in order to provide more clarity into the ongoing clinical trials.


mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Quazim A. Alayo ◽  
Nicholas M. Provine ◽  
Pablo Penaloza-MacMaster

ABSTRACT The unprecedented challenges of developing effective vaccines against intracellular pathogens such as HIV, malaria, and tuberculosis have resulted in more rational approaches to vaccine development. Apart from the recent advances in the design and selection of improved epitopes and adjuvants, there are also ongoing efforts to optimize delivery platforms. The unprecedented challenges of developing effective vaccines against intracellular pathogens such as HIV, malaria, and tuberculosis have resulted in more rational approaches to vaccine development. Apart from the recent advances in the design and selection of improved epitopes and adjuvants, there are also ongoing efforts to optimize delivery platforms. Viral vectors are the best-characterized delivery tools because of their intrinsic adjuvant capability, unique cellular tropism, and ability to trigger robust adaptive immune responses. However, a known limitation of viral vectors is preexisting immunity, and ongoing efforts are aimed at developing novel vector platforms with lower seroprevalence. It is also becoming increasingly clear that different vectors, even those derived from phylogenetically similar viruses, can elicit substantially distinct immune responses, in terms of quantity, quality, and location, which can ultimately affect immune protection. This review provides a summary of the status of viral vector development for HIV vaccines, with a particular focus on novel viral vectors and the types of adaptive immune responses that they induce.


2021 ◽  
Vol 8 ◽  
Author(s):  
Rajashri Bezbaruah ◽  
Pobitra Borah ◽  
Bibhuti Bhushan Kakoti ◽  
Nizar A. Al-Shar’I ◽  
Balakumar Chandrasekaran ◽  
...  

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.


Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1324
Author(s):  
Kenneth Lundstrom

Viral vectors can generate high levels of recombinant protein expression providing the basis for modern vaccine development. A large number of different viral vector expression systems have been utilized for targeting viral surface proteins and tumor-associated antigens. Immunization studies in preclinical animal models have evaluated the elicited humoral and cellular responses and the possible protection against challenges with lethal doses of infectious pathogens or tumor cells. Several vaccine candidates for both infectious diseases and various cancers have been subjected to a number of clinical trials. Human immunization trials have confirmed safe application of viral vectors, generation of neutralizing antibodies and protection against challenges with lethal doses. A special emphasis is placed on COVID-19 vaccines based on viral vectors. Likewise, the flexibility and advantages of applying viral particles, RNA replicons and DNA replicon vectors of self-replicating RNA viruses for vaccine development are presented.


2021 ◽  
Author(s):  
Chaojie Zhong ◽  
Fengliang Liu ◽  
Renee J. Hajnik ◽  
Lei Yao ◽  
Kangjing Chen ◽  
...  

Recombinant viral vectors are an important platform for vaccine delivery. Our recent study has demonstrated distinct innate immune profiles in responding to viral vectors of different families (e.g., adenovirus vs. poxvirus): while human Ad5 vector is minimally innate immune stimulatory, the poxviral vector ALVAC induces strong innate response and stimulates type-I IFN and inflammasome activation. However, impact of the innate immune signaling on vaccine-induced adaptive immunity in viral vector vaccination is less clear. Here, we showed that Modified Vaccinia Ankara (MVA), another poxviral vector, stimulated type-I IFN response in innate immune cells through cGAS-STING. Using MVA-HIV vaccine as a model, we found that type-I IFN signaling promoted the generation of humoral immunity in MVA-HIV vaccination in vivo . Following vaccination, type-I IFN receptor knockout (IFNAR1-/-) mice produced significantly lower levels of total and HIV gp120-specific antibodies compared to the wild-type (WT) mice. Consistent with the antibody response, type-I IFN signaling deficiency also led to reduced levels of plasma cells and memory-like B cells compared to those in WT mice. Furthermore, analysis of vaccine-induced CD4 T cells showed that type-I IFN signaling also promoted the generation of vaccine-specific CD4 T-cell response and T follicular helper (Tfh) response in mice. Together, our data indicate a role of type-I IFN signaling in promoting humoral immunity in poxviral vector vaccination. The study suggests that modulating type-I IFN and its associated innate immune pathways will likely affect vaccine efficacy. IMPORTANCE Viral vectors, including MVA, are an important antigen delivery platform and have been commonly used in vaccine development. Understanding the innate host-viral vector interactions and its impact on vaccine-induced immunity is critical but understudied. Using MVA-HIV vaccination of WT and IFNAR1-/- mice as a model, our study reports that type-I IFN signaling promotes humoral immunity in MVA vaccination, including vaccine-induced antibody, B-cell, and Tfh responses. Findings of the present study provide insights not only for basic understanding of host-viral vector interactions, but also for improving vaccine design by potentially modulating type-I IFN and its associated innate immune pathways in viral vector vaccination.


2019 ◽  
Vol 9 (2) ◽  
pp. 32 ◽  
Author(s):  
David Hampson ◽  
Alexander Hooper ◽  
Yosuke Niibori

Viral vector-mediated gene therapy has grown by leaps and bounds over the past several years. Although the reasons for this progress are varied, a deeper understanding of the basic biology of the viruses, the identification of new and improved versions of viral vectors, and simply the vast experience gained by extensive testing in both animal models of disease and in clinical trials, have been key factors. Several studies have investigated the efficacy of adeno-associated viral (AAV) vectors in the mouse model of fragile X syndrome where AAVs have been used to express fragile X mental retardation protein (FMRP), which is missing or highly reduced in the disorder. These studies have demonstrated a range of efficacies in different tests from full correction, to partial rescue, to no effect. Here we provide a backdrop of recent advances in AAV gene therapy as applied to central nervous system disorders, outline the salient features of the fragile X studies, and discuss several key issues for moving forward. Collectively, the findings to date from the mouse studies on fragile X syndrome, and data from clinical trials testing AAVs in other neurological conditions, indicate that AAV-mediated gene therapy could be a viable strategy for treating fragile X syndrome.


Author(s):  
Martin J. Kelly ◽  
Gerard W. O'Keeffe ◽  
Aideen M. Sullivan

Parkinson's disease (PD) is a neurodegenerative disorder characterised by the progressive loss of midbrain dopaminergic neurons, which causes motor impairments. Current treatments involve dopamine replacement to address the disease symptoms rather than its cause. Factors that promote the survival of dopaminergic neurons have been proposed as novel therapies for PD. Several dopaminergic neurotrophic factors (NTFs) have been examined for their ability to protect and/or restore degenerating dopaminergic neurons, both in animal models and in clinical trials. These include glial cell line-derived neurotrophic factor, neurturin, cerebral dopamine neurotrophic factor and growth/differentiation factor 5. Delivery of these NTFs via injection or infusion to the brain raises several practical problems. A new delivery approach for NTFs involves the use of recombinant viral vectors to enable long-term expression of these factors in brain cells. Vectors used include those based on adenoviruses, adeno-associated viruses and lentiviruses. Here we review progress to date on the potential of each of these four NTFs as novel therapeutic strategies for PD, as well as the challenges that have arisen, from pre-clinical analysis to clinical trials. We conclude by discussing recently-developed approaches to optimise the delivery of NTF-carrying viral vectors to the brain.


Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1122
Author(s):  
Juan García-Arriaza ◽  
Mariano Esteban ◽  
Daniel López

There is a need to develop a highly effective vaccine against the emerging chikungunya virus (CHIKV), a mosquito-borne Alphavirus that causes severe disease in humans consisting of acute febrile illness, followed by chronic debilitating polyarthralgia and polyarthritis. In this review, we provide a brief history of the development of the first poxvirus vaccines that led to smallpox eradication and its implications for further vaccine development. As an example, we summarize the development of vaccine candidates based on the modified vaccinia virus Ankara (MVA) vector expressing different CHIKV structural proteins, paying special attention to MVA-CHIKV expressing all of the CHIKV structural proteins: C, E3, E2, 6K and E1. We review the characterization of innate and adaptive immune responses induced in mice and nonhuman primates by the MVA-CHIKV vaccine candidate and examine its efficacy in animal models, with promising preclinical findings needed prior to the approval of human clinical trials.


Sign in / Sign up

Export Citation Format

Share Document