DNA of herpes found in human remains from the Iron Age: how the virus has changed over 2500 years.

According to ТСН: Scientists have for the first time obtained direct evidence that a common childhood virus – human herpes virus type 6 – infected people as far back as the Iron Age, and in some cases even integrated into the human genome.

A team of researchers analyzed nearly four thousand human remains from archaeological sites across Europe. As a result of the study, they managed to restore eleven ancient genomes of the HHV-6A/B virus. The oldest samples come from a girl who lived in what is now Italy between 1100 and 600 BC. Other samples were found in medieval burials in England, Belgium, Estonia, and Italy.

HHV-6B currently infects most children under two years old and is the cause of roseola – an illness often accompanied by febrile seizures. After primary infection, the virus usually 'sleeps' in the body, but in some cases, its DNA can integrate into human chromosomes and be passed down through generations. This condition is currently observed in about one percent of people.

It is these hereditary forms of the virus that were found in ancient DNA. Several inhabitants of medieval England turned out to be carriers of integrated HHV-6B, thus becoming the oldest known individuals with such a type of genetic 'marker'. In the Belgian location of Sint-Truiden, specialists found both variants of the virus – HHV-6A and HHV-6B – in one community.

Evolution of the virus

Comparing ancient genomes with modern ones has allowed researchers to trace the virus's evolution over more than 2500 years. They also discovered that the two related strains – HHV-6A and HHV-6B – evolved differently: the former likely lost the ability to integrate into human DNA early on, while the latter retained this property to this day.

Scientists emphasize that now there is first-time evidence that the virus, which still infects most children, became part of the human genome during the Iron Age and has preserved this 'hereditary presence' in certain family lines to the present day.

It should be noted that archaeologists also reported unexpected findings in one of the most important cities of the Roman Empire.

The research conducted by scientists opens new horizons in understanding the evolution and history of viruses that accompany humanity. The discovery of ancient forms of herpes may help in the development of new methods of treatment and prevention of diseases caused by these viruses, as well as allow for a better understanding of how viruses evolve alongside their hosts.