Are humans at risk from a frozen virus?

Due to climate change and the increase in technology, we are now able to explore areas of the planet that were previously out of reach. The continent of Antarctica is almost twice the size of Australia and we have only been able to explore less than 5% of the current land that is exposed, leaving millions of square miles of soil and rock hidden under the ice that could be home to all kinds of things. A single teaspoon of soil contains more individual bacteria lifeforms than there are people on Earth, and it isn’t unreasonable to think that there could be something trapped under all of that soil we can’t get to.

The big question is if we are at risk from anything that could have survived frozen for thousands of years underground.

(Pandoravirus yedoma – nicknamed the zombie virus)

What have they found so far?

At the start of 2024, there were many media outlets that released stories about a new find in Siberia that everyone was calling the zombie virus, with titles claiming it could wipe out humanity or would be the next big pandemic. Turns out that it was a virus that was frozen about 30,000 years old and has the ability to infect and kill amebas, a single-celled microorganism.

The oldest ever found and revived virus came from a sample that was taken 16 meters below a lake in far eastern Russia and was dated to be 48,500 years old. This is the current world record holder for the longest frozen and revived single-celled organism and was named Pandoravirus yedoma.

In 2003, a team took a core sample from an ice cap in the Qinghai-Tibetan plateau they found bacteria within, the ice was dated to be around 750,000 years old.

What could be down there and how could it have survived?

When something freezes it expands, and in mammals this will cause their cell walls to stretch to the point where they rupture and the cell dies, which is why it’s impossible to freeze a mammal without them dying. Other types of organisms have much more flexible cells and don’t rely on blood or oxygen to be pumped around their bodies to survive, and are able to survive conditions that other species can’t, like being frozen for example.

Many creatures on Earth can be partially frozen and make a full recovery, but for anything that is multi-celled, this can only happen in small amounts for short periods. If a life form was simple enough and was able to withstand the expansion from freezing, then theoretically there is no maximum time it could survive in the right conditions.

As for if there’s anything down there that could be dangerous to us, just by probability alone it’s almost certain that the enormous amount of land that’s still trapped below the ice will be home to something harmful, but whether it will be able to actually harm us or not is another question.

Thawed-out viruses and bacteria have a hard time surviving in a new climate

So far, whenever a single-celled life form has been thawed out and revived, it has had great difficulty staying alive for very long in today’s climate. When these viruses existed, the areas of the world they lived in would have been much colder, wetter, or some kind of other environmental factor that the virus was adjusted to living in. If all of the ice on earth disappeared and the millions of square miles of land previously covered were now exposed to the world, it’s highly likely that the vast majority of things that thawed out would quickly die and not be able to adjust to a new climate.

So are humans at risk from a frozen virus?

It’s always fun for the media to release a story about the end of the world whenever a dig discovers something that has been frozen for a long time, but in reality, we are at much less risk from a frozen virus than we are from the ones we already have on earth. Anything frozen would have to mutate and adapt before it even had the chance to cause harm, and the only conditions they could do this without dying would be in controlled environments within labs.