Vaccine against Ebola developed

By Dr. Ananya Mandal, MDDec 7 2011

Researchers have developed a vaccine that protects mice against a deadly form of the Ebola virus.

Ebola was first identified in 1976 in Sudan and Zaire, which is now the Democratic Republic of the Congo and Ebola fever kills more than 90% of the people it infects. Ebola is among the most lethal diseases known to humans, according to the World Health Organization.

Ebola is transmitted via bodily fluids, and can become air borne. Sufferers experience nausea, vomiting, internal bleeding and organ failure before they die. Although few people contract Ebola each year, its effects are so swift and devastating that it is often feared that it could be used against humans in an act of bio-terrorism.

The researchers say that this is the first Ebola vaccine to remain viable long-term and can therefore be successfully stockpiled. The results are reported in the journal Proceedings of National Academy of Sciences.

All previously developed vaccines have relied on injecting intact, but crippled, viral particles into the body. Long-term storage tends to damage the virus, paralyzing the vaccine's effectiveness.

The vaccine was created using a tobacco plant, by introducing a protein from the outside of the virus into the plant. The resulting product is an “immune complex,” a combination of the virus protein and an antibody, designed to spur the body’s defenses against the infection. Traditional vaccines are made from weakened or inactivated viruses.

The vaccine protects 80% of the mice injected with the deadly strain, and survives being “dried down and frozen,” said biotechnologist Charles Arntzen who was involved in its development. “If Ebola is ever deliberately introduced as a bioterrorism agent, we would pull this out and begin using it,” said Charles Arntzen, a vaccine specialist at Arizona State University in Tempe, Arizona. He said the next step is to try the vaccine on a strain of Ebola that is closer to the one that infects humans.