|Merck's Ebola vaccine candidate being readied for Phase III trials in Sierra Leone.--Courtesy of CDC|
Ebola vaccine frontrunner Merck ($MRK) is planning to submit its candidate for regulatory approval in 2017, but that doesn't mean everyone else has thrown in the towel and gone home. Russian Health Minister Veronika Skvortsova announced that an Ebola vaccine developed in that country did well in Phase I and II trials, and will enter further testing in Guinea, Agence France-Presse reported.
According to AFP, the vaccine, dubbed GamEvac-Combi, was developed at a government vaccine research institute and showed "encouraging" results in early trials. Further details about the vaccine were not disclosed.
The WHO secretariat is "actively hoping" to study the data, WHO spokeswoman Fadela Chaib told AFP in an email.
Meanwhile, competitors GlaxoSmithKline ($GSK), Johnson & Johnson ($JNJ), Gaithersburg, MD-based Novavax ($NVAX) and Baltimore-based Profectus all have candidates in the clinic. J&J and GSK are testing their candidates--both adenovirus-based--with booster doses from Bavarian Nordic and Rockville, MD-based Emergent BioSolutions ($EBS), respectively. Novavax is working on a recombinant nanoparticle jab, while Profectus' candidate is based on a vesicular stomatitis virus.
Adding another virus vector to the mix is a team of researchers from the NIH, University of California, Riverside, and Plymouth University, who are using a common herpesvirus--cytomegalovirus--to present Ebola proteins in a vaccine. The vaccine provided protection in a nonhuman primate study.
In theory, the team said in a statement, the herpesvirus-based vaccine can be made to produce Ebola proteins at different points in time following vaccination. This particular vaccine presented Ebola antigens at a later time, resulting in high antibody levels, but no detectable T-cell response toward Ebola, the statement said. The researchers hope to be able to bias the immune response in a vaccine toward antibodies or T cells, which can be exploited for Ebola well as for other infectious and noninfectious diseases.
And at the annual American Association for the Advancement of Science meeting, a pair of scientists discussed the groundbreaking "ring" trial, in which Merck's Ebola candidate posted 100% efficacy in interim results. The strategy involved identifying Ebola cases and the "ring" of susceptible people around those cases to stop the spread of the virus. Ira Longini of the University of Florida and Dr. Ana Maria Henao Restrepo, a WHO medical officer, highlighted the "ring" structure as a way not only to respond to epidemics--including Zika--but also to carry out clinical trials for diseases where it would be unethical to give trial participants a placebo, i.e., when the risk of becoming infected and dying is high.
- here's the AFP story about Russia
- here's the Plymouth University release
- and here's the release about the ring study