In light of a recently published study by an international team of researchers, it has become apparent that our understanding of the origins of Smallpox may require revising. The study suggests that the occurrence of Smallpox can be traced back as far as the 8th century, during the Viking age.
Smallpox in the Viking Age
The Viking Age refers to a period in the Middle Ages when the Norsemen – the name attributed to Scandinavian Vikings – embarked on a series of colonizations, conquests, and trades across Europe. The study reveals that Smallpox was existent during this era. This raises questions about the disease’s associations with the Norsemen’s travels, possibly even reaching North America in the 9th and 10th centuries.
About Smallpox
Smallpox is a contagious disease caused by the Variola Virus (VARV). Transmission occurs through droplets released during coughing or sneezing and direct face-to-face contact. It is one of the deadliest diseases known to mankind but is also the only one successfully eradicated by vaccination.
Eradication and the Vaccine
The World Health Organization (WHO) announced the complete eradication of Smallpox in 1980 after a global immunization campaign utilizing the smallpox vaccine. Edward Jenner discovered the first effective vaccine in 1796.
The Origins and Evolution of Smallpox
Historical uncertainty surrounds the origins of Smallpox. The earliest confirmed case was found in the mummified remains of a 17th century child in Lithuania, though written records suggest the existence of the disease long before this.
The recent study recovered the Variola virus sequence from 13 Northern European individuals, including 11 from 600-1050 CE, coinciding with the Viking Age. Findings suggest that the smallpox virus was circulating among humans as far back as 1700 years ago, around the time of the Western Roman Empire’s decline and subsequent mass Eurasian migrations.
Interestingly, the genetic makeup of the recovered viral strain from the Viking era differs from the modern strain eradicated in 1979-1980. Both strains descended from a common ancestor but diverged approximately 1700 years ago.
The study also proposes that smallpox began as a less dangerous illness. However, due to mutations causing a reduction in the active gene count of the virus, it became more deadly over time.
Implications of the Research
Though this study does not impact our understanding of the current spread of the Covid-19 pandemic, it does shed light on how viruses may evolve over time to become more lethal. Moreover, it reinforces how diseases such as Smallpox, plague, and Hepatitis B all have histories closely linked with major prehistoric migration events.
This research contributes to our knowledge of how diseases affect human populations, helping answer key questions: Do migrations carry diseases to new areas? Or does the emergence of a disease trigger these mass movements?
By reconstructing the genetic history of Smallpox, we enhance our understanding of diseases – fundamental knowledge for predicting and preparing for future pandemics.