Initial Genetic Characterization of the 1918 “Spanish” Influenza Virus

TLDR

The 1918 “Spanish” influenza pandemic killed at least 20 million people, making it the worst infectious pandemic in history. The study aims to understand the origins and exceptional virulence of the 1918 virus to aid future pandemic prediction. RNA was extracted from a formalin‑fixed, paraffin‑embedded lung tissue sample of a victim, and nine coding‑region fragments of hemagglutinin, neuraminidase, nucleoprotein, matrix proteins 1 and 2 were sequenced. The sequences indicate a novel H1N1 influenza A virus belonging to the human–swine subgroup rather than the avian subgroup.

Abstract

The “Spanish” influenza pandemic killed at least 20 million people in 1918–1919, making it the worst infectious pandemic in history. Understanding the origins of the 1918 virus and the basis for its exceptional virulence may aid in the prediction of future influenza pandemics. RNA from a victim of the 1918 pandemic was isolated from a formalin-fixed, paraffin-embedded, lung tissue sample. Nine fragments of viral RNA were sequenced from the coding regions of hemagglutinin, neuraminidase, nucleoprotein, matrix protein 1, and matrix protein 2. The sequences are consistent with a novel H1N1 influenza A virus that belongs to the subgroup of strains that infect humans and swine, not the avian subgroup.