In response to the Ebola outbreak that has occurred across West Africa, scientists around the world are scrambling to develop a vaccine against the disease. Now, a study by researchers from the National Institutes of Health reveals the creation of a vaccine that has generated long-term immunity against the Ebola virus in monkeys, and the vaccine is currently entering its first phase in clinical trials on humans. If the current Ebola outbreak is any indicator, the fatality rates during Ebola outbreaks are high indeed. As of August 31st this year, the World Health Organization (WHO) states that there have been an estimated 3,685 cases of Ebola and 1,841 deaths from the disease in West Africa, with numbers only getting higher.
There is currently no vaccine for Ebola, although scientists have been working to develop one for quite some time now. An international research team has rapidly sequenced 99 Ebola virus genomes in an attempt to better understand the virus and find ways to potentially contain it. According to recent report in the Annals of Internal Medicine, an experimental drug called ZMapp appeared to treat Ebola in two men who contracted the infection in Liberia. ZMapp, which has only been tested in monkeys, has yet to be approved for public use by the US FDA.
In a recent study, the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases (NIAID) claim to have developed a vaccine based on the chimpanzee-derived adenovirus vector, a chimpanzee “cold” virus. Previous efforts to create an Ebola vaccine have included the use of human adenoviruses, but the researchers explain that since a lot of humans have previously been exposed to these, their immune systems are set up to neutralize them. As such, the researchers decided to use chimpanzee adenoviruses that the human immune systems haven’t come across, testing them on macaque monkeys. They discovered that inoculation with the cold virus alone provided short-term and limited long-term protection against EBOV, one of the most common and deadly forms of the Ebola virus, which is responsible for the majority of the latest Ebola outbreak. The researchers found that being injected with the chimpanzee cold virus protected the monkeys against EBOV for 10 months. The vaccine appeared to increase the number of T cells in the monkeys, which in turn defended the immune system against the virus.
Even though this study assessed the vaccine’s ability to protect against EBOV, the team believes that it could also serve to protect against another common form of the virus, SUDV. As a result of these findings, the National Institutes of Health recently announced that the vaccine will enter phase 1 clinical trials to test its effectiveness against EBOV and SUDV in humans.
