Top 10 Unsolved Virus Mysteries
#10: Are They Even Alive?
This seems like a pretty basic fact to know, but scientists disagree on whether or not viruses actually count as alive. It depends on your definition of life. Viruses evolve, reproduce, and are made of the same basic stuff as other life forms: DNA or RNA. But they don’t meet other definitions — like having cells or making their own energy. Since a virus is essentially just a piece of loose genetic code wrapped up in a delivery mechanism, it’s totally inert until it comes in contact with a living cell. So, it’s not clear whether they count as a full life form or just a piece of stray genetic machinery that powers up when it gets the chance.
#9: How Do We Defend Against Them?
In September 2019, the Global Preparedness Monitoring Board became the latest experts to warn that we were overdue for a global pandemic - one we were nowhere near ready for. Months later, they were proven right. To date, the death toll from COVID-19 remains in the hundreds of thousands, far from their worst-case projection of 80 million. But it has shown us exactly how difficult it is to even slow down the spread of a contagious disease with a long incubation period in the age of air travel. Someone could travel across the globe and contact dozens of people before showing symptoms. So if we’re going to prevent this happening again, we’d better come up with something better than temperature checks.
#8: How Did Viruses Evolve?
As far as we can tell, viruses are really old. Since they can infect all types of life, from protozoans to fungi to animals, researchers think it’s likely they share a common ancestor at least as old as the earliest of those host species. But how did they actually evolve? Well, there are plenty of theories — maybe they came from a rogue strand of mutant DNA that broke off from early cellular life. Maybe they share a common ancestor with bacteria and split off to become simpler while their relatives got more complex. Short of building a time machine with an electron microscope strapped to it, though, there’s no way yet to know which one’s right for sure.
#7: What Does All the Viral DNA in the Human Genome Do?
Did you know . . . you’re part virus? Actually, we all are. See, when a virus infects a living cell it edits the host’s DNA to make it replicate more viruses. And across the vast history of life on earth, some of those edits stuck. The result? 100,000 sequences in human DNA that originated as viral add-ons. That’s about 8% of our total genome. And while we think most of it is cancelled out by our cells’ processes, some of it definitely isn’t. For example, scientists are studying a protein called Hemo, that comes from viral DNA in fetuses and placentas. They think some proteins like this might actually be beneficial to us. But for many more, we don’t know what they’re doing at all.
#6: Are Viruses the Original Form of Life?
Viruses have been around so long and their structure is so simple that biologists think they may be older than cellular life itself. If that’s true, the first viruses must have been very different to viruses today. The viruses we know need to infect a living cell to reproduce, so that would have to be a later feature. In the 90s, French scientists found a virus in a nuclear cooling tower so big they thought it was a bacterium at first. Its genetic code was so complex, it could actually create some proteins on its own without a living cell. Some researchers say this is a clue about what the earliest viruses were like - and may even suggest a shared ancestor between viruses and cellular life.
#5: Are We Just Viruses with Better PR?
One theory suggests that cells with nuclei - like the ones that make up our bodies - are actually a symbiosis between a virus and an early type of cell. The idea is that a virus moved into some early type of nucleus-free cellular life. And either the arrangement proved beneficial to both of them or the virus took over. Either way, they started reproducing together instead of separately, and eventually evolved into the multicellular, nucleus-based life we know today. If that’s true, it means you and everyone you’ve ever met is a big pile of viruses sloshing around in cellular mech suits.
#4: Why Do Vaccines Sometimes Make Viruses Worse?
To be clear right off the bat: this is something that happens occasionally when testing new vaccines. Any vaccine you get from your doctor has already been tested and determined safe. This is not a reason to worry about getting vaccinated. It is a challenge when it comes to developing new vaccines though. In an effect known as antibody-dependent enhancement, some vaccines lead to antibodies that actually make people MORE vulnerable to the disease they’re supposed to protect them from. We’re still not sure exactly how it works, but it’s shown up in cases of dengue fever, zika and coronaviruses. The possibility that it could worsen cases of COVID-19 is one reason it’s so important to test any vaccines slowly and carefully.
#3: How Can We Make Viruses Work for Us?
It’s not all bad news. In a way, viruses are just pieces of infinitesimally small cellular machinery. And as we learn to edit genetic code, it’s becoming more and more possible to change the way that machinery works. There are scientists investigating their use for everything from using them as nanomachines to make changes to the world on the molecular level to programming them to infect and kill cancer cells. In fact, there’s been at least one viral cancer treatment approved by the FDA since 2015. It’s a modified herpes virus used to kill melanoma cells with much milder side-effects than traditional chemotherapy.
#2: How Many Countries Have Viral Weapons?
There’s a dark side to putting viruses to work, however — it’s just as easy to change their genetic code to hurt people as it is to help them. In the decades after the Second World War, biological weapons programs flourished around the world. The US program included experiments on unwitting Americans; in one infamous incident in 1955, whooping cough was released in Tampa Bay. Today, most countries are party to the Biological Weapons Convention, a treaty that bans the production and stockpiling of bioweapons - in force since 1975. However, there are at least 16 countries in the world with known or suspected bioweapons programs. And there’s no way of knowing that countries committed to the Biological Weapons Convention are actually complying.
#1: How Big Of a Threat Are They to Us?
In 2020, we’ve had a taste of just how disruptive viruses can be. Air travel and global connectivity mean disease can spread faster than ever before. And while bacterial infections can be killed off with antibiotics, antibiotics don’t work on viruses. There aren’t as many antiviral drugs, either, so our best weapon against them is vaccines. Unfortunately, it takes precious time to develop one, as we’re all keenly aware with COVID-19. Before the current pandemic, the Global Preparedness Monitoring Board warned that the global attitude toward pandemic preparation was dangerously lax. So the real question is, can we learn enough from this one to be better prepared next time?
