Medieval parchment yields ancient sheeppox virus genomes

Overview

Updated 2 hours ago

Sheeppox has been infecting flocks for at least 3,700 years. Researchers have now pulled its DNA out of an unlikely archive: the animal skins that medieval scribes scraped, soaked and bound into books, including the 1,000-year-old York Gospels.

The study, published in Science Advances, adds 21 ancient viral genomes spanning Bronze Age settlements in Kazakhstan and Russia to manuscripts made in Britain, the Upper Rhine, Austria and France. It also shows the virus has changed remarkably little since then, which sharpens the question of how it became a sheep pathogen in the first place. Sheeppox still causes economic losses today; an outbreak was under way in Greece when the paper appeared.

Why it matters

A virus that barely changed in 3,700 years gives vaccine and diagnostic researchers a narrower set of genes to test.

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Key Indicators

Ancient sheeppox genomes sequenced

Samples range from Bronze Age sheep teeth to medieval parchment and paper.

Parchment manuscripts positive for sheeppox DNA

Documents were made between the early 8th and 14th centuries CE.

Positive folia made from calfskin

More than the sheepskin folia, an unexpected result the authors say may reflect contamination during production.

11,500–3,700 years ago

Estimated window when capripoxvirus lineages split

The range overlaps livestock domestication and the movement of sheep from the Eurasian steppe into Europe.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Louis L'Hôte

Lead author of the Science Advances study

Publishing ancient DNA research on livestock pathogens

Organizations Involved

Science Advances

Peer-reviewed journal

Published the study

The open-access journal of the American Association for the Advancement of Science, which published the sheeppox genomics paper.

York Minster Library

Cathedral library

Holds the York Gospels, one of the sampled manuscripts

The library holding the York Gospels, a high-status manuscript made in Canterbury around 990 to 1020 CE.

University College Dublin

University

Announced the findings in a research news release

The Dublin university whose research office publicised the study's findings.

Timeline

September 2026 November 2026

2 events Latest: Today

November 2026
ScienceDaily reports the parchment virus findings
Today Publication

A ScienceDaily release summarises the study, including the York Gospels sampling and the virus's genomic stability.
Today
September 2026
Sheeppox genomes sequenced from Bronze Age teeth and medieval parchment
Research

Science Advances publishes 21 ancient sheeppox virus genomes and estimates capripoxvirus lineages split 11,500 to 3,700 years ago.
September 2026

Scenarios

Older sheeppox genomes push the timeline past the Bronze Age

Possible Resolves by End of 2028

Discussed by: The study authors, who note their divergence estimate leaves earlier evolution unobserved

The paper's own conclusion is that the important genetic changes may predate the oldest sample. If museums and excavation archives yield sheeppox-positive remains from earlier pastoralist sites, the 3,700-year record extends and the divergence window narrows.

Libraries survey parchment collections for pathogen DNA at scale

Possible Resolves by Q2 2028

Discussed by: Researchers quoted in coverage of the study, who describe manuscripts as biological records

The sampling method relies on eraser rubbings rather than destructive cutting, which makes large-scale screening of bound volumes feasible. A national library or major cathedral collection announcing a systematic survey would show the approach moving from one study to routine practice.

Greek sheeppox outbreak is contained and declared resolved

Uncertain Resolves by End of 2027

Discussed by: Louis L'Hôte, who cited the outbreak as evidence the pathogen still matters economically

The study appeared while Greece was fighting a sheeppox outbreak. Control depends on vaccination, movement restrictions and culling. A formal declaration that the country is free of the disease would close the immediate animal-health chapter the authors invoked.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1967–1980

Smallpox eradication (1980)

A global vaccination campaign run by the World Health Organization drove variola virus, which killed hundreds of millions of people over centuries, out of circulation. The last natural case was recorded in Somalia in 1977.

Then

The World Health Assembly declared smallpox eradicated in 1980.

Now

Smallpox became the template for eradicating a human virus, and its genome became a reference point for studying how poxviruses change over time.

Why this matters now

The sheeppox researchers use smallpox as their contrast case: smallpox's genome altered substantially, while sheeppox stayed nearly the same for millennia.

1994–2011

Rinderpest eradication (2011)

A cattle plague that caused repeated famines in Africa and Asia was targeted by a coordinated vaccination and surveillance campaign. The last known outbreak was in Kenya in 2001.

Then

The Food and Agriculture Organization and the World Organisation for Animal Health declared rinderpest eradicated in 2011.

Now

It became the first animal virus eradicated, and the campaign established genomic surveillance as part of livestock disease control.

Why this matters now

It shows that a livestock virus can be eliminated, and that the kind of genomic baseline the sheeppox study provides is useful for tracking and certifying outbreaks.

Bronze Age

Sheep move from the Eurasian steppe into Europe (roughly 5,000–4,000 years ago)

Domesticated sheep spread westward from the steppe, and woolly sheep appear in the archaeological record in the same broad period. The sheeppox study places the peak of capripoxvirus divergence in roughly this window.

Then

Livestock farming and animal-product trade expanded across Europe and Central Asia.

Now

Dense herds and long-distance movement created conditions for host-specific pathogens to establish and spread.

Why this matters now

The study's divergence estimate overlaps this movement, suggesting the virus's history is bound up with how sheep were farmed and moved.