Researchers in the US and Canada have developed vaccines that protect monkeys against the Ebola and Marburg viruses. Further testing in the next five years will show whether the vaccines can be safe and effective for humans, but the researchers are optimistic. It is the first hint of a vaccine for Marburg virus.

The research, published in Nature Medicine this weekend, suggests that the vaccines raise the chance of surviving the highly contagious diseases to around 80 per cent.

Currently, the vast majority of those who contract either disease will die, and because of the way they are transmitted, (by blood, sweat and saliva), those caring for the sick run a very high risk of becoming ill themselves. The World Heath Organisation reports that an outbreak of Marburg disease in Angola that began in late March 2005, had killed 335 of the 399 people who were infected by 27 May.

The researchers at Canada's National Microbiology Laboratory in Winnipeg, Manitoba, began by testing their vaccine on rodents. The team created the vaccine by replacing a protein in an animal virus with a protein from the Ebola and Marburg viruses.

The next step was to move to primates, with the help of the US Army. The Army's Medical Research Institute of Infectious Disease in Maryland vaccinated the monkeys, and the four weeks later, injected them with the viruses. The monkeys survived the tests.

Because of the similarity between the way the diseases affect monkeys and humans, the researchers are now hopeful that the vaccines will work for us too.

Steven Jones, a scientist involved in the study, told Reuters: "Monkeys, when they are infected, suffer almost the identical disease to humans. If we can protect them using this vaccine ... then this gives us a good deal of confidence that this will work in humans." ®

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