Tuesday, June 28, 2005
Lassa fever vaccine succeeds in Monkey test
A vaccine against Lassa fever has protected monkeys in experiment from infection with lethal doses of Lassa virus, US and Canadian scientists reported on Monday.
The study, published in the journal Public Library of Science (PLoS) Medicine, could eventually lead to development of a vaccine for human use, the researchers said.
The Lassa fever, transmitted to humans from rodents that carry the virus, is common in parts of West Africa where it causes a significant amount of death and disability among the population.
Recently, some travelers died of hemorrhagic fever in the US and Europe after being infected with this virus in West Africa. The reported cases aroused panic, but there is no preventive measure available currently to halt the spread of Lassa fever other than rodent control in affected areas.
In this new research, lead investigators Thomas Geisbert of the US Army Medical Research Institute of Infectious Diseases ( USAMRIID)and Heinz Feldmann and Steven Jones of the Public Health Agency of Canada (PHAC) developed the vaccine using a non- pathogenic form of vesicular stomatitis virus, or VSV, as a carrier.
The researchers inserted genetic material from the Lassa virus, which express the Lassa viral glycoprotein. The team then immunized four rhesus macaques with a single dose of the Lassa vaccine, while two monkeys received only the VSV "carrier" virus.
Four weeks later, all six animals were experimentally infected with a lethal dose of Lassa virus. The four vaccinated monkeys survived with no signs of clinical illness, while the two control animals died.
Posted by C. at 9:27 AM