Diverse variola virus (smallpox) strains were widespread in northern Europe in the Viking Age

Research output: Contribution to journalArticle


Smallpox, one of the most devastating human diseases, killed between 300 million and 500 million people in the 20th century alone. We recovered viral sequences from 13 northern European individuals, including 11 dated to ~600-1050 CE, overlapping the Viking Age, and reconstructed near-complete variola virus genomes for four of them. The samples predate the earliest confirmed smallpox cases by ~1000 years, and the sequences reveal a now-extinct sister clade of the modern variola viruses that were in circulation before the eradication of smallpox. We date the most recent common ancestor of variola virus to ~1700 years ago. Distinct patterns of gene inactivation in the four near-complete sequences show that different evolutionary paths of genotypic host adaptation resulted in variola viruses that circulated widely among humans.


  • Barbara Mühlemann
  • Lasse Vinner
  • Ashot Margaryan
  • Constanza de la Fuente Castro
  • Morten E. Allentoft
  • Peter de Barros Damgaard
  • Anders Johannes Hansen
  • Sofie Holtsmark Nielsen
  • Lisa Mariann Strand
  • Jan Bill
  • Alexandra Buzhilova
  • Tamara Pushkina
  • Ceri Falys
  • Valeri Khartanovich
  • Vyacheslav Moiseyev
  • Marie Louise Schjellerup Jørkov
  • Palle Østergaard Sørensen
  • Yvonne Magnusson
  • Hannes Schroeder
  • Gerd Sutter
  • Geoffrey L. Smith
  • Christian Drosten
  • Ron A.M. Fouchier
  • Derek J. Smith
  • Eske Willerslev
  • Terry C. Jones
  • Martin Sikora
External organisations
  • University of Cambridge
  • Charité - University Medicine Berlin
  • University of Copenhagen
  • University of Chicago
  • Curtin University
  • Norwegian University of Science and Technology
  • University of Oslo
  • Thames Valley Archaeological Services
  • Peter the Great Museum of Anthropology and Ethnography
  • Frederikssund Museum
  • Erasmus University Medical Center
  • Wellcome Trust Sanger Institute
  • University of Southern Denmark
  • German Center for Infection Research (DZIF)
  • Institute of Molecular Biology, National Academy of Sciences of Armenia
  • Lomonosov Moscow State University
  • Roskilde Museum
  • Malmö museer
  • Ludwig-Maximilian University of Munich
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Public Health, Global Health, Social Medicine and Epidemiology
  • Archaeology
Original languageEnglish
Article numbereaaw8977
JournalScience (New York, N.Y.)
Issue number6502
Publication statusPublished - 2020
Publication categoryResearch