1918 Killer Flu Virus Sequence in GenBank®

In the fall of 2005, scientists announced that a killer had been resurrected. The 1918 Spanish Flu virus was reconstituted using sequences in GenBank combined with newly sequenced influenza RNA polymerase. The fully reconstituted 1918 virus showed a frightening degree of pathogenicity, causing severe lung pathology and rapid death in laboratory mice unlike contemporary flu viruses that are not lethal to laboratory mice. Another finding, that the 1918 virus was likely a human-adapted avian virus, increases fears that another deadly pandemic virus arising from the H5N1 avian flu viruses in circulation today may be possible.

Sequences for the 1918 virus were obtained from the remains of victims of the deadly wave of influenza that swept across North America in the fall of 1918 killing an estimated 675,000 Americans. The most complete set of flu sequences came from a lung biopsy taken in 1997 from the frozen remains of a flu victim who died in Teller Mission (now called Brevig Mission), Alaska, in November of 1918. Other flu DNA segments were obtained from formalin-fixed paraffin-imbedded tissues archived by the Armed Forces Institute of Pathology. These were taken from two soldiers, one who died of the flu at Fort Jackson, South Carolina, and another at Camp Upton, New York, both in September of 1918. Finding these 1918 virus segments at the NCBI is most easily accomplished using the taxonomy database. A global query for 'influenza A virus' finds one match in taxonomy. This link leads to the Taxonomy Browser where the different subtypes and strains are shown. The 1918 virus is of the H1N1 subtype. The three strains from 1918 are Influenza A virus (A/Brevig Mission/1/1918(H1N1)), Influenza A virus (A/South Carolina/1/18 (H1N1)), and Influenza A virus (A/New_York/1/18 (H1N1)). The NCBI taxonomy entry for the Brevig Mission virus is shown in Fig. 1.

Figure 1. Taxonomy report for the 1918 Brevig Mission virus. The Nucleotide and Protein links retrieve the eight genomic RNA segments and the ten encoded proteins of the virus. The sequence of the 1918 virus shows unique sequence differences from contemporary H1N1 viruses, but it remains unclear how each these contribute to the pathogenicity of the strain. What is clear is that the overall effect of these differences is to produce a devastating virus, unmatched in its ability to wreak havoc.