An Ebola Vaccine Is Not the Answer

In a widely shared Onion article from a few days ago, scientists "announced" that an Ebola vaccine was still 50 white people away. This was a jab at pharmaceutical companies, who, cynics think, will only set their R&D wheels in motion if there's money on the horizon. Hundreds of poor Africans die? No drugs. Old rich men can't have sex? All the drugs.

That's not entirely true, of course. It does take a big pharmaceutical company to get a vaccine approved for use in humans, but drug companies aren't evil—at least not irrationally so. They tend to throw resources into vaccine development if there's a chance that they might recoup their investments. GlaxoSmithKline, for example, is already pretty far along in developing a vaccine for malaria.

But malaria kills a child every minute. Meanwhile, here's a look at how many people die from Ebola compared with other deadly diseases:

Ebola's on there, I promise. It's just that, with 900 or so deaths, it's barely a blip compared to the others. Ebola is horrifying, but it's also sporadic—between the big 2001 outbreak and this one, only a few dozen people have gotten sick every year or two. And the current outbreak has spread among a handful of poor countries that all have weak health infrastructure. Drug companies aren't eager to develop a vaccine if they aren't sure who would buy it.

That's why the job of funding vaccines for diseases like Ebola usually falls to governments. And in this case, the U.S. government is actually working on a vaccine that has already been shown to work in monkeys. If it proves effective in humans, it could start to be used as early as next year.

But even if a vaccine works, it would be a stretch to say we could confidently use it to prevent another Ebola outbreak, like we did with smallpox or (largely) with polio:

Ebola is too unpredictable. The last outbreak occurred in 2012 in the Democratic Republic of Congo, which is 2,500 miles from Sierra Leone, the heart of the current epidemic. Short of vaccinating the entire continent of Africa, there's no good way to predict who is going to get the disease next. 

"We don't know where the next outbreak is going to be," Kartik Chandran, an associate professor of microbiology and immunology at Albert Einstein College of Medicine, told me. "It strikes like lightning and then disappears." 

There are several strains of Ebola. The current strain is ZEBOV, or Zaire virus, but there are also Sudan and Cote d'Ivoire versions. A vaccine would have to work against all of them.

Vaccines don't work that well in fast-moving epidemics. There are a few things you can do with a vaccine once an outbreak starts. One is immunizing healthcare workers and the families of infected patients. Sometimes doctors try "ring vaccination," or targeting residents of villages on the perimeter of the outbreak in an attempt to isolate and quash it.

But most vaccines take a few weeks to provide immunity, and even then, they don't always control the disease's spread. Donald Allegra, chair of infection control at Newton Medical Center in New Jersey, remembers trying to halt the advance of measles in a Cambodian refugee camp in the 1970s. "We vaccinated 10,000 kids, but didn't have an effect on the outbreak," he said. "Vaccines and acute outbreaks don't work very well together."

People don't trust Western healthcare workers. This has been a problem throughout this epidemic—local villagers have been blocking streets and preventing doctors from entering. Imagine what would happen if we tried to preemptively vaccinate thousands of people who not only are skeptical of Western medicine, but have never heard of Ebola. Fewer than half of Americans get the flu vaccine, after all.

"We have enough trouble vaccinating everyone against polio," Allegra said. "There's always a feeling that it's a Western intrusion."

That's not to say that we shouldn't develop an Ebola vaccine—it could prove essential in the event of a bioterrorism attack, for example, or if the vaccine was also effective as a treatment. But it might not be our best hope for stopping this and future outbreaks.

Instead, we want a treatment. Chandran recently won an NIH grant to try to find an Ebola cure, and so far he's isolated one protein that seems essential for the virus to be able to thrive in the body. People without this protein appear to be immune.

ZMapp, the experimental antibody given to the American doctor currently fighting Ebola, Ken Brantly, is another possibility. But there are still enormous gaps in our understanding of Ebola's biology.

"Why are 40 percent surviving?" asked Gillian Woollett, senior vice president for FDA policy at Avalere Health. "What is it that they have that allows them to survive? There's a fair bit of basic research that remains to be done."

There's a lot to be outraged by in the Ebola outbreak: The fact that there's no treatment for Ebola, and 60 percent of infected people will suffer bloody, painful deaths. Or the fact that Africans seem to get slammed by one health disaster after another. Or the fact that poverty and feeble governments make those disasters worse. Or the fact that it took an American doctor falling ill for Americans to start paying attention. Or the fact that the far more deadly epidemics of tuberculosis and malaria rarely command media attention in the way Ebola does. 

The lack of an Ebola vaccine, meanwhile, doesn't make the short list of Africa's health problems.