Recently, new information has been presented about the origin of smallpox disease in a study conducted by an international team of researchers.

• In their study by researchers, it was told that the existence of smallpox disease dates back to the 8th century BC. 
• The Viking Age was the period during the Middle Ages when the Norsemen colonized, conquered, and traded throughout Europe, reaching North America in the 9th and 10th centuries.
• There has always been ambiguity about the origin of smallpox.
• Yet, based on written records, the earliest evidence of smallpox was found in the mummified remains of a 17th-century Lithuania child.

Chickenpox:

• Chickenpox is an infectious disease caused by the Variola Virus (VARV).
• Spread: It is transmitted through droplets released during contact with an infected person, coughing, and sneezing.
• Eradication: Smallpox is one of the deadliest known diseases to mankind which can only be eradicated by vaccination.
• After the global smallpox vaccination campaign led by the World Health Organization (WHO) in 1980, it was declared completely eliminated.
• Vaccine: The most effective vaccine for smallpox was discovered in the year 1796 by Edward Jenner.

Key findings of the latest research:

• Trace the sequence of the virus: Variola virus sequences were obtained from 13 individuals from northern Europe, 11 of which date from 600–1050 CE.
• Virus presence throughout Europe: Based on the earliest written records, a sequence of viruses in southern and western Europe combined with smallpox was present in the form of smallpox among all European peoples in the late 6th century.
• According to the study, the smallpox virus was still present among people around 1700 years ago when the Western Roman Empire collapsed and people migrated into Eurasia.
• Genetic Structure: According to the study, the genetic structure of the virus strain obtained from 11 individuals is different from the modern/present version of the virus, which has been eradicated in the year 1979-80.
• The Viking type of virus was previously unknown but is now an extinct group or clade of viruses.
• A clade is a group that includes a common ancestor and all descendants of that ancestor (living and extinct).
• Both modern smallpox and its ancient variant/type have their origins from a common ancestor that diverged 1700 years ago.

Importance of Research:

• It is important to note that smallpox is the latest among many other diseases whose history has been rewritten in recent years by their ancient DNA analysis.
• Earlier in the year 2015, a study reported that a plague that killed millions of people has been traced back to the Bronze Age between 3000 and 1000 BCE in medieval Europe.
• On the other hand in the year 2018, the origin of Hepatitis B was also seen in the Bronze Age itself.
• Modes of spread: The findings of the study will help to understand the ways in which diseases have affected human populations in the past.
• Based on the facts obtained from DNA, it can be said that the origin of major diseases like plague and hepatitis B is related to their prehistoric migration/transfer. This also symbolizes the truth about smallpox.
• This study will also help to know whether migration has spread diseases to new areas or whether the origin of the disease has prompted people to relocate.