The study team involving researchers from the U.S. Army Medical Research Institute of Infectious Diseases and the National Microbiology Laboratory at the Public Health Agency of Canada reported yesterday that the vaccine that is used to protect monkeys by in preventing hemorrhagic fever in monkeys after they were exposed to the deadly Marburg virus. Could also provide the first known treatment for the infection caused by Ebola virus.
The researchers now claim that they have created a vaccine by replacing a gene from a harmless virus with a gene encoding a surface protein on the Marburg virus. In their study, which was reported in the April 27th issue of The Lancet, the researchers infected five rhesus monkeys with the Marburg virus and then injected them with the vaccine 20 to 30 minutes later. They used three other monkeys as controls infected them with the virus but were given a vaccine without the Marburg protein. They found that all five monkeys that received the Marburg protein vaccine survived for at least 80 days, while the controls died within 12 days.
Geisbert, whose team worked with colleagues at the National Microbiology Laboratory at the Public Health Agency of Canada, said that the team were very surprised at the results but stated that it may be a while before the vaccine is tested in people but he hoped it is a first step. He said that if the vaccine was so effective in monkeys given high doses of virus, it should be effective in an outbreak scenario in which people typically get lower doses.
The Ebola virus, like the Marburg causes internal bleeding at multiple sites causing hemorrhagic fever and victims usually die of multiple organ failure and shock.
Both viruses are considered to be potential bio terrorism threats. Currently there are no drugs to fight infection with Marburg virus or the Ebola, both of which are caused by a family of viruses known as filoviruses, and even treatment aimed at easing the illness and symptoms rarely work. This new study suggests the vaccine may be an effective post-infection treatment for the disease.
Marburg virus killed more than 300 people -- 90 percent of those infected -- in Angola last year. Ebola is usually somewhat less deadly and killed 254 people between 2001 and 2005 in Gabon and the Democratic Republic of Congo.