Ancient Cold Virus Genome Reconstructed from Centuries-Old Tissue Samples

An international team of scientists has successfully reconstructed the genome of a rhinovirus – the virus family responsible for the common cold – from human tissue samples dating back as far as the 1770s. This discovery, recently published on the bioRxiv server, provides fresh insights into the evolution of respiratory viruses and challenges previous assumptions about the stability of RNA viruses in historical remains.

Unearthing Viral History

Researchers analyzed lung tissue samples from a woman who died in London around 1770 and remains from another individual who died in 1877. These samples, preserved in alcohol within historical collections, allowed for the recovery of viral genetic material despite the inherent instability of RNA.

Challenges in Reconstructing Ancient RNA

Rhinoviruses contain RNA, a genetic material known to degrade rapidly after death – typically within hours. This poses a significant challenge to studying ancient viruses. However, the research team was able to reconstruct the virus genome using little genetic fragments, ranging from 20 to 30 nucleotides, while typical chains in living cells exceed a thousand nucleotides.

A Lost Viral Lineage

The reconstructed virus belongs to a rhinovirus family that is no longer in circulation today. Comparative analysis with modern rhinovirus variants suggests that the ancient virus shares a common ancestor with rhinovirus type A19 dating back to the 17th century. bioRxiv

Implications for Understanding Viral Evolution

This discovery offers a unique opportunity to understand how respiratory viruses have evolved over time. By studying the genetic makeup of ancient viruses, scientists can gain valuable insights into viral adaptation, transmission patterns, and the development of immunity. Understanding the evolution of these viruses is crucial, as RNA viruses, including coronaviruses and influenza viruses, constantly adapt to their environments.

The Broader Context of Respiratory Viruses

Respiratory viral infections are among the most common illnesses affecting humans. These infections are caused by a diverse group of viruses, and new molecular diagnostics continue to expand our understanding of the range of viruses present in respiratory samples. Beyond the common cold, other respiratory illnesses caused by bacteria and viruses, such as common human coronaviruses, are tracked by organizations like the CDC, with increased activity typically observed in the fall and winter months.