We have been quite successful in fighting 'invisible' threats such as viruses and bacteria over the last fifty years. The discovery of antibiotics fuelled many cures for infectious diseases that until then remained untreatable. Viruses are a little harder to kill, mainly because they are built in a much more simple fashion, rendering them with less vulnerabilities to exploit. Nevertheless, scientists have been able to develop some anti-viral drugs, even though some viruses remain extremely dangerous. The Ebola virus is an example, which causes haemorrhagic fever and is deadly in most cases of infection. It remains a potential threat to mankind, but luckily scientists from the National Microbiology Laboratory in Canada have developed a vaccine that seems to function as a cure.
There are a number of different species that belong to the Ebola family of viruses, and the Canadian scientists developed their vaccine for the most deadly variant: the Zaire ebolavirus. Just like the other variants, infection normally causes severe internal bleeding, eventually leading up to death of the patient. To test their new vaccine, researchers infected monkeys with the Ebola virus and assessed whether their treatment was able to save their lives. Needless, to say, this type of research cannot be performed on human beings.
A cocktail of antibodies, immunological molecules that bind to a specific target, were used to create the vaccine. They specifically aimed at a protein present on the surface of the Ebola virus, neutralizing it. Although attempts to create a vaccine with Ebola antibodies is not new, the Canadian attempt consisted of three different types of antibodies, that each recognized a specific part of said protein. Because this specific protein is needed in order for the virus to be able to infect a cell, the scientists hoped to slow down viral spread throughout the body, giving the immune system enough time to launch an attack against the virus.
A set of experiments were performed, which started with infection of the monkeys with Zaire ebolavirus. Four monkeys were given the vaccine, with the name ZMAb, 24 hours after being infected, and they all survived. Two out of four receiving the vaccine 48 hours after infection managed to survive as well. Because the vaccine was able to impair cellular infection, the immune system was given enough time to launch its own attack, eventually killing the viruses and ending the infection. A control monkey, that was left untreated, died five days after infection. The results show that the vaccine appears to be working, but time is still of the essence if infection is suspected.
Ebola is able to wipe out large parts of the population if it manages to spread. So far, outbreaks have been restricted to Africa, but the virus could be potentially used as a biologic weapon, especially because some variants can be easily transmitted through air. Mutations could also make it more likely that the virus spreads and multiplies, which means that an effective vaccine is much needed. There is no treatment for infected patients, and because it is deadly, Ebola has been classified as biosafety level 4; the highest level a pathogen can attain. Because of that, the virus can only be studied in futuristic laboratories in which the scientists wear space-like suits.
The Canadian vaccine looks promising for future use in human patients. Because it is impossible to set up clinical trials, scientists will have to wait with their tests until we see another outbreak of the Zaire ebolavirus. Though the results look promising, studying a few monkeys is not enough to make accurate statements about its efficacy, but larger studies would mean more monkeys will have to die. It is likely that the vaccine will be used on patients without making too much fuss about its safety in humans, because of the deadliness of the virus and the fact that no real treatment is available. According to the researchers, their vaccine is likely to be more effective than other experimental attempts.