Advances in Designing and Developing Vaccines, Drugs, and Therapies to Counter Ebola Virus

Abstract

Ebola virus (EBOV), a member of the family Filoviridae, is responsible for causing Ebola virus disease (EVD) (formerly named Ebola hemorrhagic fever). This is a severe, often fatal illness with mortality rates varying from 50 to 90% in humans. Although the virus and associated disease has been recognized since 1976, it was only when the recent outbreak of EBOV in 2014–2016 highlighted the danger and global impact of this virus, necessitating the need for coming up with the effective vaccines and drugs to counter its pandemic threat. Albeit no commercial vaccine is available so far against EBOV, a few vaccine candidates are under evaluation and clinical trials to assess their prophylactic efficacy. These include recombinant viral vector (recombinant vesicular stomatitis virus vector, chimpanzee adenovirus type 3-vector, and modified vaccinia Ankara virus), Ebola virus-like particles, virus-like replicon particles, DNA, and plant-based vaccines. Due to improvement in the field of genomics and proteomics, epitope-targeted vaccines have gained top priority. Correspondingly, several therapies have also been developed, including immunoglobulins against specific viral structures small cell-penetrating antibody fragments that target intracellular EBOV proteins. Small interfering RNAs and oligomer-mediated inhibition have also been verified for EVD treatment. Other treatment options include viral entry inhibitors, transfusion of convalescent blood/serum, neutralizing antibodies, and gene expression inhibitors. Repurposed drugs, which have proven safety profiles, can be adapted after high-throughput screening for efficacy and potency for EVD treatment. Herbal and other natural products are also being explored for EVD treatment. Further studies to better understand the pathogenesis and antigenic structures of the virus can help in developing an effective vaccine and identifying appropriate antiviral targets. This review presents the recent advances in designing and developing vaccines, drugs, and therapies to counter the EBOV threat.

COVID-19: animals, veterinary and zoonotic links

“…The past decade and recent episodes of Zika, Ebola, Nipah, and Bird flu viruses (Munjal et al 2017;Dhama et al 2012Dhama et al , 2018Singh et al 2019), and lessons learned from previous threats of coronaviruses (SARS-and MERS-CoVs) along with advances in science have paved pace to counter emerging pathogens including the SARS-CoV-2. For this purpose, high efforts are being made to contain and control the spread of this emerging virus haunting the lives of humans and posing even now a pandemic situation.…”

New and emerging infectious diseases (Ebola, Middle Eastern respiratory syndrome coronavirus, carbapenem-resistant Enterobacteriaceae, Candida auris): Focus on environmental survival and germicide susceptibility

“…[33][34] Although there are currently no antiviral drugs approved by the US Food and Drug Administration (FDA), a number of therapies are under investigation including antibody-based therapies (eg, convalescent blood products, monoclonal antibodies), and drugs and small molecules (eg, Ebola virus gene expression inhibitors, and Ebola virus entry and inhibitors). [33][34][35] A number of preventive vaccines are currently in clinical trials. [33][34][35] Environmental contamination and survival Ebola virus has been isolated by cell culture from multiple body fluids of infected or convalescent patients including blood, saliva, stool, vaginal fluid, sweat, and urine for days or months after illness.…”

“…[33][34][35] A number of preventive vaccines are currently in clinical trials. [33][34][35] Environmental contamination and survival Ebola virus has been isolated by cell culture from multiple body fluids of infected or convalescent patients including blood, saliva, stool, vaginal fluid, sweat, and urine for days or months after illness. 36 Given the high volume of diarrhea and vomiting and the potential for fomite transmission, the frequency of environmental contamination and survival of Ebola virus is of high concern.…”

COVID-19, an emerging coronavirus infection: advances and prospects in designing and developing vaccines, immunotherapeutics, and therapeutics

“…[2][3][4] Many efforts have been directed to develop vaccines against human CoV infections in recent decades, but a limiting factor is the degree of cross-protection rendered by these vaccines due to their extensive sequence diversity. 5 Various vaccines, immunotherapeutics, and drug options have been explored during the recent threats of Zika, Ebola, and Nipah viruses [6][7][8] as well as against previous CoVs including SARS-and MERS-CoVs. 3,5,[9][10][11][12] These valuable options can be exploited for their potency, efficacy, and safety along with expediting other ongoing research 2,4,[13][14][15] so as to discover valuable modalities for tackling the emerging COVID-19, but as yet there is no effective vaccine or therapeutic, for which intense efforts are ongoing.…”