A Vaccine That Gives Monkeys Immunity To Ebola, Now To Be Tried On Humans
Medical scientists have come up with a vaccine that uses a genetically modified chimpanzee virus that has the same components as the two strains of the Ebola virus: Zaire and Sudan species. However, this viral vaccine does not replicate itself within the host’s body, but scientist are hoping that the host’s immunity system will react to the component of the Ebola thus developing immunity.
The monkeys that were vaccinated developed long-term immunity against the Ebola virus, raising hopes that the vaccines could work as effectively on humans too. Now scientists are embarking on human trials.
The experiments conducted by the US National Institutes of Health showed the monkeys acquired immunity for at least ten months. Trials on humans have already begun in the United States and will soon begin in the UK and Africa.
According to World Health Organization (WHO), over 2,000 lives have already succumbed to the Ebola virus in West Africa. Medical scientists have so far come up with several experimental treatments in a bid to contain the spread of the virus.
The research on animal, upon which the decision to begin trials on humans was based has been published in the Nature Medicine journal.
The journal shows how all four crab-eating macaques survived five weeks after being given what is described as a fatal dose of the Ebola virus. In the following ten months after immunization, only half of the macaques survived.
As cited by BBC, Dr Anthony Fauci, the Director of the US National Institute of Allergy and Infectious Diseases, said, “The good part of this vaccine is that at five weeks or earlier you get full protection… The sobering news is the durability isn’t great, but if you give a boost, a second shot, you make it really durable. We knew this worked in the monkey months ago and based on this paper we started human trials.”
As of now, these medical trials are the best evidence on just how successful a vaccine would be on humans. The first person to undergo the human trials was a 39-year-old woman, who took part in the trials last week.
Another separate trial will be conducted against just the Zaire species of the Ebola virus. These human trials will be taking place in the United States, UK, Mali and Gambia. WHO said, safety data would be available by November 2014, and if the results prove the vaccine to be safe, the vaccine will be rolled out in West Africa immediately. The first people to receive to receive the vaccine would be healthcare workers and staff working on the frontline in areas affected by the Ebola outbreak.
WHO has however cautioned against people getting detracted from using the already proven ways of controlling the infection from previous outbreaks.
Prof Jonathan Ball, a virologist from the University of Nottingham, said, “This is really encouraging data. The degree of protection seen with the chimpanzee adenovirus alone – which will be used in one of the human clinical trials planned for the UK, Mali and the Gambia – was still pretty impressive, especially when the animals received Ebola virus within a few weeks of vaccination.
This is important as it would keep the dosing regimen simple and could still provide good protection in the sort of outbreak that we are seeing in Western Africa at the moment.”