Ignorance Is No Comfort

Kate Winslet and Larry Clark in Contagion 

Dear Art—

Is Contagion a public health campaign? I don’t think so. The Centers for Disease Control didn’t produce it; Hollywood did. It’s a movie—but it’s a movie for which the creators talked to people who actually deal with viruses and epidemics. And for that, I give them a lot of credit. It’s rare to find a movie that tries to show what scientists actually do, rather than putting an actor in a lab coat and having him fight bug-faced aliens.

I’m a journalist, not a virologist, but from my experience I think that when it comes to the scientific process, they got a lot right. Last year I spent time in Ian Lipkin’s lab at Columbia, for example, to write a profile of him for the New York Times. A steady stream of mysterious viruses arrives in the mail, and it’s the job of Lipkin’s team to figure out what they are. If a deadly new virus did start sweeping across the United States, what you see in Contagion offers a pretty good picture of how scientists would try to figure out what we were dealing with. Art, you had nerdy niggles; I had my share of nerdy pleasures. When the scientists are trying to identify the virus, it doesn’t just pop on a computer screen in full molecular glory the way it might on CSI. Instead, they saw a phylogeny appear—an evolutionary tree showing how the killer virus is related to known viruses. Hunting for viruses is, in large part, genealogy. I think it’s the only phylogeny I’ve ever seen in a movie theater.

There is, of course, another question of verisimilitude that a lot of people will ask as they come out of the theater: Could that really happen? And by that I mean a new kind of virus sweeping across the world. (Warning: biohazard level 5 spoiler alert!)

Nothing exactly like what’s in the movie has happened yet. It is still science fiction—but not 28 Days Later science fiction. I certainly found the ingredients of the story to be plausible. The Contagion virus is a hybrid of microbes from bats and pigs that combined in a bat. Viruses swap parts all the time—that’s how new flu pandemics get their start, as strains from birds, pigs, and humans mingle in the same cell. Many of our most dangerous pathogens jumped from animals, and bats are gleeful incubators for lots of deadly, exotic viruses, some of which—like SARS—have spilled over into our species, and some of which haven’t made the journey (yet).

Viruses adapt to the human body as they adapt to our species, and they can change dramatically in the process. Bird flu is a mild gut disease, and human flu is a potentially fatal respiratory disorder. Lipkin recently found evidence that hepatitis C—a liver disorder in humans—may have started out as a pneumonialike disease in dogs.

Once the Contagion virus starts to spread among movie stars and other humans, it travels fast and proves to be horrifically deadly. There’s certainly plenty of evidence from SARS and the 2009 swine flu that planes are excellent ways to spread a virus around a planet. Even before widespread civil aviation, the flu of 1918 was able to spread worldwide. Nor is it fantasy for a virus to be as deadly as the one in Contagion. Smallpox, Ebola, Marburg—there are plenty of real viruses with high kill rates.

But can those ingredients be mixed together into a plausible whole? That’s much harder to say. Once SARS emerged from bats, it did not become a global killer. Instead, after it was identified and public health measures were put in place, it disappeared and hasn’t been seen since. The frightening Ebola virus described in Richard Preston’s The Hot Zone causes a few hundred deaths at most each year. The disease burns itself out in humans, and then shrinks back into some animal host. The H1N1 2009 swine flu, on the other hand, spread quickly, but proved to be a relatively mild pandemic. The 1918 Spanish flu—the paragon of global pandemics—may have been a peculiar creature of its age, spread by wounded World War I soldiers transported on trains. The flu can open the way for bacteria to infect the lungs and cause infections; we don’t know how many of the 50 million deaths it caused then were the result of the bacteria—deaths that could have been prevented with antibiotics.

Scientists don’t actually know enough to say whether there are trade-offs that make a very fast, very deadly virus impossible. Ignorance is no comfort to me, though. And if Contagion makes people aware of what we do know, I’m not going to lose sleep about its causing pandemic panic. It might even lead people to appreciate the full scope of death caused by viruses and other pathogens—the ones that don’t have the makings of an action-packed thriller. The history of HIV—a virus from chimpanzees, which crossed over to humans about a century ago in a remote part of Cameroon, spread silently around the world for decades before it came to light, and now kills 1.8 million people a year–is like Contagion in slow motion. And it’s all too real.

The one place where I thought the movie veered from scientific reality in an important way was its ending. It’s only a matter of months before a vaccine is developed and humanity saved. As weird as it may sound, Contagion is a movie in which millions die and also has a happy ending. We’re fortunate to have vaccines for some of the worst killers, but they didn’t come overnight. In fact, virologists have been working for decades on vaccines for many other viruses like HIV and still don’t have something to give to patients. Art, I’d be curious what you, as someone who has written so much about vaccines, think about how much hope we can put in vaccines during an outbreak?

Best wishes,