1918 Spanish flu records could hold key to preventing future pandemics

November is the 90th anniversary of the return of Australian forces from Europe and marks the point at which Australian scientist tried to contain the flu outbreak that caused 50 million deaths worldwide.

Researchers from the University of Melbourne's Melbourne School of Population Health, supported by a National Health and Medical Research Council grant, are analysing UK data from the three waves of the pandemic in 1918 and 1919. Researchers are analysing the records of 24 000 people collected from 12 locations in the UK during the Spanish flu outbreak including Cambridge University, public boarding schools and elementary schools.

The 1918 flu outbreak killed healthy young people rather than children and the old, as is the usual case with severe flu outbreaks. The key to this research is to understand shy the virus was particularly severe in this group. Another striking feature is that the pandemic appeared in three waves, in the summer and autumn of 1918 and then the following winter.

One theory being examined to explain why some people were only affected in the second or third wave is that because of recent exposure to seasonal influenza virus they had short-lived protection against the new pandemic virus.

It appears that a protective feature was short-lived immunity from previous flu outbreaks - which may have protected young children and older people. This suggests that it could be possible to prevent another similar outbreak with short-lived broad-based vaccines rather than trying to provide specific immunity.