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Formula Developed for Vaccines Against All Hemorrhagic Viruses

  • Carol Pearson

The World Health Organization reported two more cases of Ebola in Guinea Friday, ending a two week period with no new infections of the deadly virus in West Africa.

While the news is disappointing, experts did not think the outbreak was over, and even if it were, Dr. Anthony Fauci at the National Institutes of Health said there will be more Ebola outbreaks in the future.

"We are going to have other Ebola outbreaks. History tells us that Ebola doesn’t just disappear and go away," Fauci said.

To prove his point, Fauci pointed out that there have been 24 outbreaks of Ebola since 1976. But it wasn't until this year that a vaccine that’s 100 percent effective was available. That's because scientists in the public and private sectors, even those from competing pharmaceutical companies, worked together to produce a safe and effective vaccine in record time.

The vaccine combines a piece of the Zaire strain of Ebola with a weakened cold sore virus. The result is vaccine that doesn't make people sick, but protects against Ebola-Zaire.

There are four different strains of Ebola virus that can affect people. "The available evidence is that a vaccine against one strain will not protect against other viruses of a different strain," according to Dr. Mark Feinberg, the chief scientist for Merck Vaccines, a branch of the pharmaceutical company that produced the vaccine for trials in West Africa. Merck is also known as MSD.

Although the current vaccine only protects against Ebola-Zaire, Feinberg said the cold sore virus, or VSV, can be combined with proteins from other strains of Ebola. He said, "The VSV approach for the Zaire Ebola strain that was tested in this study has been successfully and very effectively applied to all the other known strains of Ebola" in studies involving monkeys.

Fauci, who heads the National Institutes of Allergy and Infectious Diseases at NIH, said marrying the weakened cold sore virus with a piece of other hemorrhagic viruses could produce vaccines against the deadly Marburg virus or the less deadly but more prevalent Lassa virus.

Well before the first case of Ebola broke out in West Africa, scientists were working on vaccines for other deadly hemorrhagic viruses. Marburg, which is just as deadly as Ebola, and Lassa, a virus that is far more common in Africa than Ebola or Marburg. Up to half a million people in West Africa get Lassa fever every year and about 5,000 die from it, according to data from the World Health Organization. Lassa fever is a major health problem throughout West Africa. Fauci said. "Our original purpose before the outbreak of Ebola in West Africa, was to... have VSV as a vector and to have Marburg, Lassa and Ebola in there."

He said the research on producing vaccines against hemorrhagic viruses will go forward. The goal is to never have an Ebola epidemic again. "Our original purpose before the outbreak of Ebola in West Africa, was to do just that: to have VSV as a vector and to have Marburg, Lassa and Ebola in there. That was the original plan. When Ebola had this historic outbreak in West Africa, we put aside the plans for the others and we focused on developing just the Ebola," Fauci said.

The next time Ebola breaks out, Fauci said, public health specialists want to be prepared. Meanwhile, research continues on vaccines for all hemorrhagic viruses. The goal is to end the suffering from all hemorrhagic fevers in West Africa.