Ebola, Marburg vaccines undergoing tests in South Africa

Published 8 January 2010

Because Ebola and Marburg have been confined to Africa and outbreaks limited, drug companies have not had a financial incentive to come up with a vaccine; only the threat of bioterrorism has prompted the U.S. government to spend millions on vaccine research

An experimental vaccine against the deadly Ebola and Marburg viruses is undergoing tests at Southwest Foundation for Biomedical Research. As we reported, the Dutch pharmaceutical company Crucell, which developed the vaccine under a $30 million contract with the National Institute of Allergy and Infectious Diseases, will pay the foundation up to $2.7 million to test it in animals. No treatment exists for Ebola and Marburg, which often cause uncontrolled bleeding and death.

While occasional outbreaks still occur in Africa, where both originated, U.S. health officials are concerned they might be used as biological weapons. The World Health Organization (WHO) estimates Ebola has sickened at least 1,850 people and killed more than 1,200 since it first was discovered three decades ago.

MySanAntonio’s Don Finley writes that the vaccine combines noninfectious parts of the Ebola and Marburg viruses with an adenovirus, similar to the common cold but that does not cause symptoms. The adenovirus acts as a vehicle to carry the other viral particles into cells so the immune system can recognize them and mount an attack.

“I think it’s promising,” said Jean Patterson, chairwoman of virology and immunology at Southwest Foundation. “The early data showed that it was extremely promising in rodents, and that’s why they needed to come to us.”

The foundation, which operates a biosafety level 4 lab capable of housing the most deadly infectious agents, has worked with both viruses before. Last year, Patterson and scientists from Emory University published results from a study of a different Ebola vaccine. That vaccine, engineered from bocavirus, prevented Ebola infection in mice.

Patterson said the odds are good that an effective vaccine will become available. Because the diseases have been confined to Africa and outbreaks limited, however, drug companies have not had a financial incentive to come up with a vaccine. Only the threat of bioterrorism has prompted the government to spend millions on vaccine research.

“I think if we just had the resources before this, we would have had an Ebola vaccine,” she said. “There’s just been no market. The virus is extremely stable. And unlike AIDS or respiratory syncytial virus, you can develop an immune response that’s lifelong.”