Original drawing of the 1918 Spanish flu virus

1918 flu virus reborn

The 1918 Spanish flu virus has been reconstructed – and is helping to explain why flu can be so deadly

The Spanish flu virus disappeared from circulation many years ago, leaving unexplained the reasons for its severity. In 2005, however, a US team used material from an Alaskan flu victim buried in permafrost since November 1918 and from lung sections of a US soldier stored by army pathologists to piece together the sequence of the virus, which was then reconstructed from synthetic DNA.

The reborn virus is lethal to mice, grows rapidly in human cells, and infects but does not kill pigs. Notably, nearly every one of its genes seems to have contributed to its deadliness.

Although recreating a lethal virus might seem risky, studies of the 1918 virus have told us much about the effects of different flu proteins and how the virus spreads. The research is also providing new leads for antiviral drug design. Studies are carried out in specialised containment facilities to prevent the virus escaping.

Lead image:

Drawing of the 1918 Spanish influenza virus, showing congestion of vessels, infiltration of round cells and thickening of membrane.

Wellcome Library, London CC BY NC


About this resource

This resource was first published in ‘Influenza special issue’ in October 2009 and reviewed and updated in January 2015.

Microbiology, Genetics and genomics, Health, infection and disease, History
Influenza special issue
Education levels:
16–19, Continuing professional development