Dental analysis of 1,400-year-old Viking remains confirms infection with the smallpox virus. Experts suggest these masterful seafarers may have accelerated its spread across Europe.
Smallpox ravaged humanity with eruptions of hundreds of pustules across the body. Eradicated in 1980, this devastating disease, caused by the strictly human variola virus and spread via respiratory droplets, claimed over 300 million lives in the 20th century alone.
The origins of human smallpox remain shrouded in mystery. Genomic research traces the virus's independent evolution to about 3,400 years ago, but direct evidence was scarce before the 17th century—making this new study, published in Science, a major breakthrough.
Researchers detected smallpox traces in the remains of 11 Vikings from around 1,400 years ago, sourced from Denmark, Norway, Russia, the UK, and Sweden's Öland island.
These ancient strains differ markedly from modern variants. "They show a very different pattern of active and inactive genes," explains Dr. Barbara Mühlemann of the University of Cambridge. "This offers crucial insights into how the variola virus evolved, potentially becoming milder or more virulent over time."
Though genetically distinct from 20th-century smallpox, these strains confirm the virus's presence 1,400 years ago. "We now know Vikings had smallpox," affirms co-author Eske Willerslev.
The Vikings' extensive travels may have fueled the disease's dissemination across Europe, much like modern pandemics. Willerslev draws parallels to COVID-19, which has claimed over 600,000 lives globally.
"Just as global travel rapidly spread COVID-19, Vikings likely propagated smallpox—by ship instead of plane," he notes.
It's unclear if this ancient strain was as lethal as later versions. While detectable virus levels persisted in these individuals' remains after 1,400 years, it doesn't prove smallpox caused their deaths.
