Deadly Ebola 'disarmed'

2008-01-22 12:02

Chicago - US researchers have devised a way to genetically disarm the deadly Ebola virus in a development that could speed research into a vaccine against the bug or drugs to treat people who have been infected with it, a study released on Monday said.

The investigators discovered that by removing a single gene from the virus, they can prevent it from replicating or multiplying, effectively neutralising the virus and making it much safer to study.

The virus has eight genes. One of those, VP30, makes a protein that enables it to replicate in host cells. Without VP30, the virus cannot grow.

"The altered virus does not grow in any normal cells," said Yoshihiro Kawaoka, a professor of pathobiological sciences at the University of Wisconsin-Madison School of Veterinary Medicine.

The Ebola virus first emerged in 1976, with outbreaks in Congo and Sudan. Subsequent, sporadic outbreaks have occurred in Gabon, Ivory Coast and Uganda.

Humans infected with one of three strains of the bug can develop Ebola hemorrhagic fever, an illness characterised by fever, diarrhoea, vomiting and in some cases internal and external bleeding.

There is no cure and mortality rates are high - anywhere from 50 to 90% of those infected die from the disease.

Up to this point, research into the virus has been limited to a handful of highly specialised labs around the globe that can demonstrate compliance with stringent bio-containment protocols.

The latest development could change that situation, enabling many more laboratories to study the exotic virus, and explore options for vaccine development and screening for antiviral compounds, the paper said.

"This is an emerging virus and it's highly lethal, but because (of the bio-containment protocols) knowledge of this virus is limited," said Kawaoka.

The study appears in the Proceedings of the National Academy of Sciences.

- AFP