Ebola vaccines in clinical trial: The promising candidates

Abstract

Ebola virus disease (EVD) has become a great threat to humans across the world in recent years. The 2014 Ebola epidemic in West Africa caused numerous deaths and attracted worldwide attentions. Since no specific drugs and treatments against EVD was available, vaccination was considered as the most promising and effective method of controlling this epidemic. So far, 7 vaccine candidates had been developed and evaluated through clinical trials. Among them, the recombinant vesicular stomatitis virusbased vaccine (rVSV-EBOV) is the most promising candidate, which demonstrated a significant protection against EVD in phase III clinical trial. However, several concerns were still associated with the Ebola vaccine candidates, including the safety profile in some particular populations, the immunization schedule for emergency vaccination, and the persistence of the protection. We retrospectively reviewed the current development of Ebola vaccines and discussed issues and challenges remaining to be investigated in the future.

A single dose of a vesicular stomatitis virus-based influenza vaccine confers rapid protection against H5 viruses from different clades

“…27,28 In addition, VSV-based replicating vaccines are efficacious at lower doses compared to non-replicating approaches and do not require adjuvants. 52 In conclusion, we have developed two VSV-based vaccine candidates, VSV-EBOV-HAfl and VSV-HAfl, that provide proof-ofconcept for rapid protection against HPAI virus infection that are mediating cross-neutralizing responses. If clinical development confirms the promise of being fast-acting and strongly protective, VSV-based vectors might be a promising approach for the development of a pan-H5 influenza virus emergency vaccine.…”

Perspectives towards antiviral drug discovery against Ebola virus

“…The first outbreak resulted in 54 EVD cases (38 confirmed and 16 probable) and 33 deaths (overall case‐fatality ratio of 61%) as of 24 July, 2018 (declared the end of this outbreak), while the latter is ongoing, which includes 238 cases (203 confirmed and 35 probable) and 155 deaths resulting in a case‐fatality rate of 65.1% (as of 21 October, 2018) . Preclinical efforts toward specific EBOV countermeasures have been enduring for years with first treatment and vaccine clinical trials conducted during the 2013 to 2016 EBOV outbreak in West‐Africa . During the DRC outbreaks, the countermeasures were evaluated in West‐Africa EVD outbreak and demonstrated their clinical efficacy.…”

“…In addition, a small number of studies (case reports) exists for the experi countermeasures has been enduring mental use of anti‐Ebola antiviral and vaccine leads . EBOV vaccine development has already been covered in previously published reviews . In brief, the recent update includes the development of replication‐competent rVSV‐ZEBOV (rVSV) used in May‐June 2018 Equateur DRC outbreak in a ring vaccination trial (Phase III; NCT03161366), which proved to be well tolerated with improved efficacy and safety .…”

“…Although the 2014‐2016 outbreak highlighted several therapeutic compounds that successfully crossed Phase I clinical trials, some of them indicated safety concerns . The clinical trials conducted during the outbreak lacked proper controls and statistical power due to the severity and urgency of the disease .…”

Fighting Ebola: A Window for Vaccine Re-evaluation?

“…To date, seven vaccine candidates have entered clinical safety trials (reviewed [1–3]). Of these, three have progressed to efficacy trials after completion of Phase I trials and include ChAd3-ZEBOV, Ad26-EBOV/MVA-EBOV, and rVSV-EBOV.…”