Over the past ten years, Jean-Michel Claverie, a professor of economics and bioinformatics at Aix-Marseille University in France, has been on the lookout for something called "zombie viruses."

These are viruses that lie dormant but could potentially infect living beings even after being frozen for hundreds or thousands of years.

Just recently, he made a remarkable discovery: the oldest known zombie virus, estimated to be around 48,500 years old. This finding raises important questions about the impact of these frozen viruses on human health.

Scientists Uncover 48,500-Year-Old Zombie Virus

Scientists have made an intriguing discovery by unearthing a virus that is believed to be around 48,500 years old, possibly making it the oldest virus ever found.

This ancient virus was found within the frozen layers of Siberian permafrost. This finding suggests that viruses can remain preserved and still retain their ability to infect hosts for extended periods of time.

To ensure safety, the scientist, Claveria, has focused on studying viruses that only infect amoebas, which are single-celled organisms.

His team successfully isolated 13 viruses from samples of Siberian permafrost. When these viruses were introduced to petri dishes containing amoebas, all of them managed to invade the organisms.

By using radiocarbon dating techniques on the permafrost samples, they determined that the youngest virus was around 27,000 years old, while the oldest one had been frozen for a staggering 48,500 years, setting a new record for the revival of a "zombie" virus.

What Is Permafrost?

Permafrost is a term used to describe frozen ground that stays below 32 degrees Fahrenheit for two or more years. It can be found in regions like Alaska, Canada, and Siberia, covering a significant portion of the land.

Permafrost plays a crucial role because it stores vast amounts of carbon. However, with climate change, the permafrost is thawing, causing the stored carbon to be released into the atmosphere.

This release of carbon contributes to global warming, making it an important concern for our planet's temperature.

How Does Permafrost Preserve Things So Well?

Permafrost is an extremely cold environment where the ground is completely frozen. The unique thing about permafrost is that it lacks oxygen and bacteria, which prevents the decay of organic material.

This special preservation process, known as mummification, allows plants and animals to stay intact for thousands of years.

Scientists have discovered numerous well-preserved specimens in permafrost, some of which have been dated to be more than 50,000 years old using a technique called carbon dating.

What Do These Zombie Viruses Mean For Human Health?

Due to global warming, the Arctic region is experiencing increased temperatures, leading to the thawing of the frozen landscape. This process exposes previously trapped microbes and other organisms to the surface environment.

The discoveries made by researchers have sparked concerns regarding the potential implications for animal and human health in the face of climate change.

"We view these amoeba-infecting viruses as surrogates for all other possible viruses that might be in the permafrost," Claverie told CNN.

"We see the traces of many, many, many other viruses, so we know they are there. We don't know for sure that they are still alive. But our reasoning is that if the amoeba viruses are still alive, there is no reason why the other viruses will not be still alive, and capable of infecting their own hosts."

Even though the viruses that Claverie and his team have examined can only infect amoebas, it doesn't mean that they haven't found other viruses that infect humans and animals too. Scientists have actually discovered remnants of viruses that can infect humans in permafrost.

To give an example, back in 1997, researchers dug up the body of a woman buried in permafrost in Alaska. When they analyzed a sample from her lungs, they found traces of DNA from the flu strain responsible for the deadly 1918 Spanish flu pandemic.

Some Evidence of Zombie Viruses Being Problematic For Humans Already Exists

During the months of July and August in 2016, a severe anthrax outbreak occurred in Siberia, impacting numerous individuals and over 2,000 reindeer. Scientists have connected this outbreak to the increased thawing of the permafrost, which was caused by unusually hot summers.

As a result of the thaw, old spores of the Bacillus anthracis bacteria reemerged from ancient burial sites or animal remains, leading to the outbreak.

"You must remember our immune defense has been developed in close contact with microbiological surroundings,", professor emerita Birgitta Evengård at Umea University's Department of Clinical Microbiology in Sweden told CNN.

"If there is a virus hidden in the permafrost that we have not been in contact with for thousands of years, it might be that our immune defense is not sufficient. It is correct to have respect for the situation and be proactive and not just reactive. And the way to fight fear is to have knowledge."

How Likely Is It That A Zombie Virus Could Infect Humans?

While researchers suggest studying these viruses to take proactive measures, they want to avoid causing immediate panic because many aspects remain unclear. One major question is how long and how effectively a thawed virus can survive, considering that present-day conditions differ significantly from those tens of thousands of years ago.

Moreover, viruses require a host to survive. The viruses preserved in permafrost exist in areas with minimal human presence, making it uncertain how they would find a host once thawed. It's important to note that not all viruses are harmful; some are harmless or even beneficial to living organisms.

However, there are valid reasons for concern. As the Earth warms, it's not just viruses that may reemerge. The growing accessibility of Arctic regions due to new industrial opportunities is likely to attract more people.

This raises the risk of humans encountering dormant viruses, including zombie viruses, and potentially leading to problems if proper precautions are not taken.

"We're really unclear as to how these microbes are going to interact with the modern environment," said climate scientist Kimberley Miner at the NASA Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, California.

"It's not really an experiment that I think any of us want to run."

According to experts, the most effective approach is to strive for preserving the permafrost in its frozen state. This entails ongoing efforts to combat climate change. By keeping the Arctic region colder, we enhance our chances of maintaining the integrity of the permafrost.