The researchers who once studied WoW's Corrupted Blood plague are now fighting the coronavirus

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WoW: Shadowlands

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In 2005, a surprise plague swept through World of Warcraft, killing off entire servers of players while Blizzard scrambled to stop it. The infamous Corrupted Blood incident didn't pose any of the real danger we're currently facing with coronavirus Covid-19, which has killed more than 5,000 people and infected at least 137,000 so far. But back in 2005, the idea of an epidemic in an MMO captivated scientists who played the game. They saw WoW's crisis as a tool to model future epidemics and wrote a paper about it. More than a decade later, they're helping save lives by researching Covid-19.

"I'm an infectious disease epidemiologist, so emerging infectious diseases are kind of my wheelhouse," says Dr. Eric Lofgren, who now works at Washington State University, in one of the US states hardest-hit by coronavirus so far. Lofgren's research is focused on "healthcare-associated infections," meaning he and his colleagues are working to understand how hard Covid-19 will impact the US healthcare system. That means gathering and analyzing data on how likely patients are to be hospitalized and need respirators, and how likely the infection is to spread to the doctors and nurses taking care of them.

For me, it was a good illustration of how important it is to understand people's behaviors

Dr. Eric Lofgren

"One of the things we are finding, if we look at both Wuhan and Italy, is there's a huge demand on the healthcare system, and that's a genuinely serious concern here in the United States," he says. "So essentially validating what a bunch of hospitals are doing right now, preparing, and a little bit bracing for the worst."

I thought it might be a stretch to compare Dr. Lofgren's current work on a global epidemic to his past research paper on World of Warcraft, written back in 2007. But Dr. Lofgren is quick to point out some significant parallels and talk about how his time researching (and playing) WoW has affected his current work on Covid-19.

"For me, it was a good illustration of how important it is to understand people's behaviors," he says. "When people react to public health emergencies, how those reactions really shape the course of things. We often view epidemics as these things that sort of happen to people. There's a virus and it's doing things. But really it's a virus that's spreading between people, and how people interact and behave and comply with authority figures, or don't, those are all very important things. And also that these things are very chaotic. You can't really predict 'oh yeah, everyone will quarantine. It'll be fine.' No, they won't." 

Lofgren has recently been playing WoW Classic and says Corrupted Blood often comes up, with people reminiscing and hoping that Blizzard will launch a pre-patch version of the raid so it can happen all over again. That may seem a little morbid given the reality of coronavirus, but he says those chats, and games like Plague Inc., give people a way to talk about an epidemic, and better understand it, with a bit of detachment. The 2011 disaster movie Contagion has shot to the top of rental charts recently for the same reason.

(Image credit: Eric Lofgren and Nina Fefferman)

Corrupted Blood's lethality was a real annoyance for players who wanted to visit WoW cities like Ironforge, but of course it wasn't truly dangerous. No real lives were lost. We don't yet know the true mortality rate of Covid-19, but research continues to evolve and indicate that initial assumptions that it was little worse than the flu were significant underestimates. The problem with a low mortality rate, Dr. Lofgren points out, is that it makes it seem like no big deal: "Except a small number multiplied by a big number can still be a really big number." 

From WoW to TED

(Image credit: Ran Balicer)

Another researcher, Dr. Ran Balicer, also wrote about Corrupted Blood. He's busy studying coronavirus and sent me his TED speech from 2018, which touches on using games like WoW in research.

It's not about individual risk, but about the risk you pose to others, whose vulnerability to Covid-19 may even be invisible to you. For someone who often gets bronchitis or has severe asthma, for the elderly and immunocompromised, your small risk could expose them to a much greater one.

"To pull it back to a Corrupted Blood analogy, and something I've been thinking about—one of the critiques we got from a lot of people, both gamers and scientists, was over this idea of griefing," Dr. Lofgren says. "How griefing isn't really analogous to anything that takes place in the real world. People aren't intentionally getting people sick. And they might not be intentionally getting people sick, but wilfully ignoring your potential to get people sick is pretty close to that. You start to see people like 'oh this isn't a big deal, I'm not going to change my behavior. I'm going to the concert and then going to see my elderly grandma anyway.' Maybe don't do that. That's a big takeaway. Epidemics are a social problem... Minimizing the seriousness of something is sort of real-world griefing."

I emailed Dr. Nina Fefferman, who co-authored the Corrupted Blood study, who works across the country from Dr. Lofgren at the University of Tennessee. She says she also found their research in Azeroth invaluable when it comes to understanding the social side of epidemics. 

"It led me to think really deeply about how people perceive threats and how differences in that perception can change how they behave," Dr. Fefferman writes. "A lot of my work since then has been in trying to build models of the social construction of risk perception and I don't think I would have come to that as easily if I hadn't spent time thinking about the discussions WoW players had in real time about Corrupted Blood and how to act in the game based on the understanding they built from those discussions."

The equivalent to WoW players chatting about how to deal with the virus is now playing out across social media with Covid-19. Dr. Fefferman says that all her current work "focuses on how small decisions from individuals can lead to big changes for entire populations." She's studying how the age of patients and how they're tested is impacting our understanding of how Covid-19 is progressing. So far in the United States, our testing has been woefully limited, and likely means there are many more Covid-19 cases than we currently know.

Dr. Lofgren doesn't have any good news to share about a vaccine—expect that to be a long time coming. The same goes for the likelihood of this coronavirus receding in a few weeks as winter turns to spring. He says there isn't much evidence to support that this virus is seasonal, and early research using latitude as a proxy for temperature hasn't been encouraging. If it does turn out to be seasonal, following the pattern of influenza or MERS, which is a coronavirus, that means Covid-19 could re-emerge in the fall.

The response this week across the US, and in many other countries, has been to cancel schools, send workers home, and ban large public gatherings to prevent the spread of the virus. Dr. Lofgren says this kind of strong reaction is actually important: "It's hard once a disease gets really well-established in a population to put that genie back in the bottle."

Hakkar, the raid boss who caused the plague

Hakkar, the raid boss who caused the plague (Image credit: Blizzard)

It might already be too late for that. The US could have been better prepared to deal with the coronavirus, but "we have over the last couple years reduced our ability to respond to epidemics," Dr. Lofgren says. Some top experts in this field left the US government in 2018, though claims that the CDC has had its funding slashed have been misleading. But it's undeniable that the US and UK government's, and many others, have been unprepared for this epidemic.

"Corrupted Blood was this unexpected black swan event. We treat this [coronavirus] as if it's unexpected, but nature is really good at getting people sick," Dr. Lofgren says. "If you think again in gaming terms, we're making saving throws against new emerging diseases all the time. And sometimes you fail… We have epidemics recur with some degree of frequency. It's sort of like getting rid of people who predict earthquakes because you haven't had an earthquake in awhile. Well, yeah, you're gonna have another one."

The best thing we can all do is avoid underestimating the severity of the situation. No, you don't need to hoard toilet paper or face masks (healthcare professionals really need those). Yes, you can leave your house—but think about minimizing trips, avoid touching your face, practice the Elmo sneeze, and for god's sake, wash your hands. If you need a meme to remind you how long you should be watching, Dr. Lofgren is partial to Dune's Litany Against Fear.

And if you want an epidemiologist's advice on how to deal with the loneliness of working from home in isolation—personally, he suggests a raid. Zul'Gurub, which caused the Corrupted Blood Incident, will hit WoW Classic in April.

Wes Fenlon
Senior Editor

Wes has been covering games and hardware for more than 10 years, first at tech sites like The Wirecutter and Tested before joining the PC Gamer team in 2014. Wes plays a little bit of everything, but he'll always jump at the chance to cover emulation and Japanese games.


When he's not obsessively optimizing and re-optimizing a tangle of conveyor belts in Satisfactory (it's really becoming a problem), he's probably playing a 20-year-old Final Fantasy or some opaque ASCII roguelike. With a focus on writing and editing features, he seeks out personal stories and in-depth histories from the corners of PC gaming and its niche communities. 50% pizza by volume (deep dish, to be specific).