The virus has been evolving with us since at least the Iron Age
From the bones of Iron Age children and medieval villagers, scientists have recovered the genomic fingerprints of a virus that has shadowed humanity for at least twenty-five hundred years. An international team reconstructed eleven ancient genomes of Human betaherpesvirus 6A and 6B — a pathogen that quietly infects nearly every living person — proving that its intimate relationship with our species, including its rare capacity to weave itself into our very chromosomes, is not a modern accident but an ancient covenant. The discovery transforms a virus identified only in the 1980s into one with a documented biography stretching back to Iron Age Italy, and raises new questions about what it means to carry, in every cell of one's body, a passenger inherited from ancestors long buried.
- A virus present in roughly ninety percent of all humans has now been traced back over 2,500 years, shattering assumptions about how recently it entered our lives.
- The rarest and most consequential feature of HHV-6 — its ability to permanently integrate into human chromosomes and be inherited like a family trait — has been confirmed in medieval English skeletons, the earliest known carriers on record.
- Screening nearly four thousand ancient skeletal samples across Europe, researchers recovered only eleven viral genomes, a painstaking hunt through faint genetic signals buried in millennia-old bone.
- An unexpected evolutionary split has emerged: HHV-6A appears to have lost its chromosomal integration ability over time, while HHV-6B retained it — a divergence with living consequences, as inherited HHV-6B has been linked to angina and heart disease.
- The inherited forms of both viruses are disproportionately common in the UK today, making the discovery of ancient British carriers a medically urgent thread worth pulling.
Researchers have extracted viral DNA from bones more than two thousand years old, rewriting the known history of a pathogen that most humans carry without ever knowing its name. An international team from the University of Vienna, University of Tartu, Cambridge, and University College London screened nearly four thousand skeletal samples from archaeological sites across Europe, searching for traces of Human betaherpesvirus 6A and 6B. They recovered eleven ancient viral genomes. The oldest belonged to a young girl buried in Iron Age Italy between 1100 and 600 BCE.
HHV-6B is the more familiar strain — the cause of roseola infantum and the leading trigger of febrile seizures in infants. By age two, roughly ninety percent of children carry it, after which it retreats into dormancy for life. What sets these viruses apart is their rare ability to integrate into human chromosomes, effectively becoming heritable genetic material. About one percent of people today carry such integrated copies in every cell of their body. Scientists had long suspected this integration was ancient; the new genomic evidence confirms it.
Both viral species turned up in medieval England, Belgium, and Estonia, with HHV-6B also appearing in Italy and early historic Russia. Several individuals from medieval England carried chromosomally integrated HHV-6B — the earliest inherited herpesvirus carriers yet identified. Lead researcher Meriam Guellil noted that detecting these ancient integrated forms was exceptionally difficult, given how faint the genetic signal is in remains where only one percent of individuals would carry the inherited variant.
Comparison of ancient and modern genomes revealed a striking divergence: HHV-6A appears to have lost its integration capacity over evolutionary time, while HHV-6B retained it. Charlotte Houldcroft of Cambridge's Department of Genetics highlighted that inherited HHV-6B has been associated with angina and heart disease — a finding made more pressing by the fact that inherited forms of both viruses are more prevalent in the UK than elsewhere in Europe. Published in Science Advances, the study gives a virus discovered only in the 1980s a documented past stretching back to the Iron Age, written in the bones of the long dead.
Researchers have pulled viral DNA from the bones of people who died more than two thousand years ago, and what they found rewrites the timeline of a virus that touches nearly every human alive today. An international team led by scientists at the University of Vienna and University of Tartu screened nearly four thousand skeletal samples from archaeological sites across Europe, hunting for traces of Human betaherpesvirus 6A and 6B—two closely related viruses that most children encounter before their second birthday. They found eleven ancient viral genomes. The oldest came from a young girl buried in Iron Age Italy sometime between 1100 and 600 BCE.
HHV-6B is the more familiar of the two. It causes roseola infantum, commonly called sixth disease, and is the leading culprit behind febrile seizures in infants and toddlers. About ninety percent of children carry it by age two, though most experience only a mild illness before the virus settles into a dormant state that lasts a lifetime. What makes these viruses unusual is their ability to integrate directly into human chromosomes—to become, in effect, part of the host's own genetic code. This happens rarely, in roughly one percent of people today, but when it does, the viral sequence can be passed down through generations like any other inherited trait. Scientists had long suspected this integration was ancient, but suspicion is not proof. The ancient genomes now provide it.
The research team, working across the University of Cambridge and University College London as well, found both viral species circulating in medieval England, Belgium, and Estonia. HHV-6B also appeared in samples from Italy and early historic Russia. The Belgian site of Sint-Truiden yielded the most cases, with both viruses present in the same population. Several individuals from medieval England carried inherited forms of HHV-6B integrated into their chromosomes—the earliest known carriers of chromosomally integrated human herpesviruses on record. Meriam Guellil, the lead researcher, noted that finding these ancient integrated copies was difficult work. The virus is present in almost all humans at some point, but only about one percent carry inherited versions in every cell of their body, making the genetic signal faint and easy to miss in ancient remains.
By comparing the ancient genomes with modern viral sequences, the researchers could trace where in the chromosomes the viruses had integrated and how long those integrations had persisted. The data revealed something unexpected: HHV-6A appears to have lost its ability to integrate into human DNA over the course of its evolutionary history, while HHV-6B retained the capacity. This divergence suggests the two viruses have evolved along different paths even as they coexisted with their human hosts for millennia. Charlotte Houldcroft, from the Department of Genetics at Cambridge, pointed out that carrying an inherited copy of HHV-6B has been linked to angina and heart disease—a connection that makes the discovery of ancient British carriers particularly significant, since inherited forms of both viruses are more common in the UK today than elsewhere in Europe.
The study, published in Science Advances, extends the known history of HHV-6 back more than twenty-five hundred years. The virus was only discovered in the 1980s, making this archaeological evidence a kind of retroactive biography. Modern genetic analysis had suggested the virus might have been evolving alongside humans since our species migrated out of Africa, but that remained speculation. Now there is direct genomic proof of its presence in the deep human past, written in the bones of the dead and read by the living.
Citas Notables
Modern genetic data suggested HHV-6 may have been evolving with humans since our migration out of Africa. These ancient genomes now provide first concrete proof of their presence in the deep human past.— Meriam Guellil, lead researcher, University of Vienna
Carrying a copy of HHV-6B in your genome has been linked to angina and heart disease. These inherited forms are more common in the UK today compared to the rest of Europe, and this is the first evidence of ancient carriers from Britain.— Charlotte Houldcroft, Department of Genetics, University of Cambridge
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that we found this virus in ancient bones? It's not like we can treat people from two thousand years ago.
It matters because it changes how we understand the relationship between viruses and humans. We thought HHV-6 was something modern, something we discovered recently. Now we know it's been with us since at least the Iron Age, evolving alongside us the whole time.
So the virus has been integrating into our chromosomes all that time?
Not all that time—that's the interesting part. HHV-6B has been doing it for at least twenty-five hundred years. HHV-6A seems to have lost that ability somewhere along the way. We don't know when or why yet.
And the inherited copies—the ones passed down like genes—how common were they in ancient times?
We can't say for certain. We only find them in about one percent of people today, and they're easier to spot in ancient remains because they're in every cell. But the fact that we found them at all, in medieval England and elsewhere, tells us this wasn't a recent development. It's been happening for centuries at least.
You mentioned heart disease. Is that a new discovery?
No, that connection was already known in modern populations. What's new is finding ancient carriers. If inherited HHV-6B is linked to angina, and we now know people were carrying it in medieval times, it raises questions about how far back that health effect goes.
What happens next? What do researchers want to know?
They want to understand why HHV-6A lost the ability to integrate while HHV-6B kept it. They want to map out the virus's journey more completely—where it went, how it spread, whether it changed as it moved through different populations. And they want to understand what carrying an inherited copy actually does to human health over a lifetime.