1918 Spanish Flu Virus: Scientists Revive and Discover
Unlocking the Secrets of the 1918 Spanish Flu: Swiss Researchers Decode Virus’s Early Human adaptations
Basel, Switzerland – In a groundbreaking achievement that sheds new light on one of history’s deadliest pandemics, researchers from the universities of Basel and Zurich have successfully decoded the genome of the influenza virus responsible for the devastating 1918-1920 Spanish flu pandemic in Switzerland. Utilizing a historical specimen from UZH’s Medical Collection, the study reveals that the virus had already developed crucial adaptations to humans at the very outset of its global rampage, offering vital insights for combating future viral threats.
The Spanish flu, a catastrophic event that claimed an estimated 20 to 100 million lives worldwide, has long remained a puzzle regarding its rapid mutation and adaptation. This new research, led by paleogeneticist verena Schünemann, a professor of archaeological science at the University of Basel, marks the first reconstruction of a Swiss influenza genome from this infamous pandemic.
The team’s success hinges on a meticulously preserved, over 100-year-old virus sample. Extracted from a formalin-fixed wet specimen belonging to an 18-year-old Zurich patient who succumbed during the pandemic’s initial wave in July 1918, the sample provided the genetic blueprint for this historical pathogen.”This is the first time we’ve had access to an influenza genome from the 1918-1920 pandemic in switzerland,” stated Schünemann, the study’s last author. “It opens up new insights into the dynamics of how the virus adapted in Europe at the start of the pandemic.”
By comparing the newly sequenced Swiss genome with existing influenza virus genomes from Germany and North america, the researchers identified three key adaptations present in the Swiss strain from the pandemic’s beginning. These adaptations, which persisted throughout the pandemic, considerably influenced the virus’s transmissibility and virulence.
Two of these critical mutations enhanced the virus’s resistance to a specific component of the human immune system. This resistance is vital, as it represents a significant barrier to the transmission of avian-like flu viruses from animals to humans. The third identified mutation targeted a protein within the virus’s membrane, improving its ability to bind to receptors in human cells. This enhancement made the virus more resilient and demonstrably more infectious.
The challenge of sequencing ancient RNA viruses, like influenza, is considerable due to RNA’s rapid degradation. Though,the research team,including first author Christian Urban from UZH,developed an innovative new genome-sequencing method. This novel technique significantly improves the recovery of ancient RNA fragments from preserved specimens, paving the way for the reconstruction of further ancient RNA virus genomes and offering a robust method for verifying the authenticity of recovered genetic material.
The study underscores the immense, yet frequently enough underutilized, potential of historical medical collections. ”Medical collections are an invaluable archive for reconstructing ancient RNA virus genomes,” commented Frank Rühli, co-author and head of the Institute of Evolutionary Medicine at UZH. “However, the potential of these specimens remains underused.”
The implications of this research extend far beyond understanding the past. The team believes their findings will be instrumental in preparing for and mitigating future pandemics. “A better understanding of the dynamics of how viruses adapt to humans during a pandemic over a long period of time enables us to develop models for future pandemics,” Schünemann explained. Kaspar Staub, a co-author from UZH, added, “Thanks to our interdisciplinary approach that combines historico-epidemiological and genetic transmission patterns, we can establish an evidence-based foundation for calculations.” This crucial work necessitates further genome reconstructions and in-depth analyses across extended historical intervals.