Ebola and Zika Are New Threats, Not New Viruses

Esther Sarah Kim

The worldwide threat of Ebola and Zika is new, but these two infectious diseases have been around for decades. The Ebola virus was first discovered in 1976, in what is now known as the Democratic Republic of the Congo. And researchers studying yellow fever in Uganda's Zika forest isolated that virus in a caged rhesus monkey nearly 70 years ago.

In both instances, scientists were intrigued, but the need to study each independently wasn't urgent enough to merit sufficient funding. Ebola was well-contained in small villages and not a threat to overcrowded urban areas. Zika caused relatively mild and short-lived symptoms. This is why, up until these recent outbreaks, researchers studied Ebola and Zika in the context of their virus categories, or genuses in scientific terminology.

Viruses that are part of the same genus may display the same symptoms. Ebola is a filovirus, a genus that also includes Marburg; both cause hemorrhagic fever. A Zika infection looks a lot like other flavivirus infections, like West Nile, dengue and yellow fever. But from a molecular standpoint, the variety of viruses in each category is still slightly different, meaning scientists are more likely to find prevention and treatment options by focusing on just one virus rather than the entire group. But they can't really do that, because this area of research is a moving target; money and manpower go where the immediate need exists. "You can't put a full-court press on every single microbe that's out there," says Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID).

But when a viral disease explodes—as Zika has in recent months—researchers reallocate money in grants that already exist for studying a disease category to focus on the problem at hand, and then seek additional funding, Fauci says. Up until recently, nearly all the funding for flaviviruses went toward research for West Nile, dengue and yellow fever, since Zika was considered "inconsequential" from a public health standpoint, Fauci notes. In 2015, $102.7 million of the NIAID's budget provided support to research projects in this virus category. But Zika is no longer the redheaded stepchild of flaviviruses. This month, President Barack Obama asked Congress for $1.8 billion to combat Zika in the U.S. and abroad, with $200 million to fund an accelerated vaccine-testing program.

The NIAID, Fauci says, will adapt the tools it used to develop a vaccine for West Nile a few years ago. "By no means are we starting from scratch," he says. He expects to have a vaccine candidate for Zika by the summer.