The largest and most complex Ebola outbreak in the history has killed more than 11,000 people and sickened more than 15,000 others so far, according to the CDC. Most of the deaths happened in Sierra Leone, Liberia and Guinea.
Investigators all over the world are attempting to develop medicines and health products in order to protect people and prevent further spread of Ebola virus (EBOV). Several diagnostic kits to detect this emergent virus are already on the market and a mobile Ebola test is in development. However, there are still no proven treatments so far and even though a few experimental vaccines have been developed, proofs that proposed vaccines would definitely protect against EBOV are still lacking. At least until now. Latest reports from the two different studies indeed show promising results.
According to the article published a week ago in Science a single dose of vaccine based on recombinant vesicular stomatitis virus expressing the EBOV glycoprotein (VSV-EBOV) injected 7 days before lethal challenge with the West African EBOV-Makona strain completely protected macaques against the virus. Besides, a partial protection was provided with a single injection of vaccine only 3 days before challenge with virus. The investigators suggested that VSV-EBOV may also protect humans against EBOV infections with relatively short time to immunity.
This was already proved in another study published two weeks ago in The Lancet. The same vaccine was tested on more than 7500 human individuals in Guinea which were in close contact with newly diagnosed Ebola patients and people who received doses without delay were 100% protected against the virus.
Despite optimistic results, there are already some speculations about real effectiveness of vaccine in human. The Conversation journal suggested three reasons which can make us doubt whether vaccine really worked or how well it worked. The reasons are the lack of placebo comparison, the way the investigators diagnosed vaccine failure and the possibility of statistical flukes. Read more about these speculations here.
By Katarina Kovac, PhD, Product Manager, BioSistemika LLC