In 2002, Hollywood out first resident Evil adaptation of the wildly popular video game, sparking a film and television franchise that continues for twenty years later. But there’s one aspect of his legacy that deserves a closer look today: the film’s fictional T-virus.

A futuristic entity known as the Umbrella Corporation is building a viral bioweapon in its lab. Soon, the virus escapes through the facility’s air ducts and causes a massive outbreak that turns people into cannibalistic zombies. The protagonist and the rest of her crew battle the zombies to prevent the disease from spreading to the outside world.

To be clear: the virus isn’t real (nor are zombies), but is it even plausible? (Spoilers ahead for Resident Evil (2002).)

Coil Science is a Reverse series that reveals the real (and fake) science behind your favorite movies and series.

Are zombie viruses real?

If you haven’t watched the movie in a while, here’s a quick recap of what the virus does: it turns people into mindless, bloodthirsty zombies with only basic motor functions, little intelligence and no memory. of work. According to the film, these human zombies “are driven by the lowest impulses, the most basic needs: the need to feed.”

Guillaume Schaffnerprofessor of infectious diseases at Vanderbilt University, says Reverse: “there is no such virus that will do that.”

However, some real viruses look like some aspect of zombie-ification, if you will. Some infectious diseases cause inflammation of the brain and affect our thinking and behavior – a condition known as encephalitis.

“You could have growing brain tumours, which cause you to do unusual things – alter your personality. Make your reasoning not very effective, and even crisis-inducing,” says Schaffner.

Some scientists compared rabies – which humans can get when an infected animal bites or scratches a human – to a zombie-like virus because of its ability to cause rage and confusion, but again, that’s because rabies causes encephalitis.

“I couldn’t think of a virus that would reduce you to very primitive functions, like looking for food,” Schaffner says.

Donald J. Alcendor, adjunct associate professor of pathology, microbiology, and immunology at Vanderbilt University School of Medicine, says Reverse there is a little discussed virus that shares some characteristics with typical zombie viruses.

This virus is the John Cunningham virus (JC for short). It is a type of polyomavirus, which is a family of DNA viruses that exists in mammals and birds. A majority of human adults have been exposed to the JC virus and don’t even know it.

“If your immune system is intact, it’s a virus you’ll carry throughout your life. And that shouldn’t be a problem for you,” says Alcendor.

The reason most of us have never heard of the JC virus is that the immune system of healthy adults can usually fight it off. But immunocompromised adults cannot fight off the virus as easily. In their body, the JC virus changes from a dormant to an active state and begins to replicate, causing progressive multifocal leukoencephalopathy (PML).

“I couldn’t think of a virus that reduced you to very primitive functions”

This condition destroys myelin, which forms a protective layer around your brain’s neurons. The individual may display some characteristics that we typically associate with zombies, including personality changes, clumsiness and stumbling, paralysis, and growling due to voice communication issues.

“If you think of anything that would give you zombie-like pathologies, I’d say the closest thing in my mind would be JC virus infection,” Alcendor says.

It is important to emphasize that people with JC virus do not attack people like zombies; most are bedridden. Yet, it is still a dangerous virus for those it infects because there is no real cure.

“I would say that 50% of people diagnosed with PML die within three to six months of diagnosis,” adds Alcendor.

Is the T virus realistic?

Here is a description of the movie virus, which explains how it resuscitates the body upon infection:

Even in death, hair and fingernails continue to grow. New cells are produced and the brain itself holds a small electrical charge… the T-virus provides a massive jolt to both cell growth and these electrical impulse traces. To put it simply: it resuscitates the body.

To put it simply: real-life viruses cannot bring the dead back to life.

“We don’t know if someone who was infected with a virus was brought back to life in some form,” Schaffner says.

The T-virus’ mechanism of stimulating cell growth — causing infected people to mutate into even scarier beings by feeding on human flesh or “fresh DNA” as the film puts it — is also highly unrealistic.

Viruses “don’t encourage cell growth,” Schaffner says, adding that they “usually destroy them.”

The T virus and Covid-19

SARS-CoV-2 – the virus that causes Covid-19 – cannot turn people into zombies. But there are some similarities between the T virus and SARS-CoV-2 that you might not have realized.

“COVID isn’t likely to make you look like a zombie, but what it can do is it can put you in a cage in a state of acute respiratory distress,” says Alcendor.

Perhaps the most interesting comparison we can make between the two viruses is how they spread. The T virus can switch from liquid transmission to airborne or blood transmission, depending on its environment, which makes it highly contagious.

While Covid-19 is primarily an airborne disease, surface transmission is still possible, although extremely unlikely. Exposure to respiratory fluids also spread the disease. To be clear: Covid-19 is not a blood-borne diseasebut it can replicate in blood cells.

It is therefore not at all uncommon for viruses to be spread by multiple routes of transmission, although a better comparison to the T virus may be norovirus, which Schaffner says is a “highly infectious” virus that can be transmitted in several ways involving personal contact.

But the route of transmission of a real virus is less likely to mutate depending on the environment, unlike the T virus. The Covid-19 virus has mutated to become more contagious, but that has not changed the way he was infecting people. But other viruses have changed the modes of transmission. The mode of transmission of the Zika virus – which doctors previously thought was only spread by mosquitoes – has mutated so that it can also infect through sexual contact.

“We had never heard of a mosquito-borne virus that could also be transmitted through sex,” Schaffner says.

But an airborne SARS-CoV-2 would be unlikely to mutate to change its transmission routes as easily as the T virus does, giving us some peace of mind in this pandemic.

“I couldn’t think of a virus that could easily mutate so that it had a radically different mode of transmission,” Schaffner says.

resident Evil (2002) is streaming now on Netflix.