They also challenged the accepted wisdom of wild birds as the major reservoir harboring the flu virus, from where it jumps to domestic birds and other species, including humans. Share this article Share 'If our model is correct, then current medical interventions, especially antibiotics and vaccines, against several pneumonia-causing bacteria, could be expected to dramatically reduce mortality, if we were faced today with a similar set of pandemic ingredients,' Worobey said. Most influenza outbreaks disproportionately kill juvenile, elderly, or already weakened patients; in contrast the pandemic predominantly killed previously healthy young adults. To maintain morale, wartime censors minimized early reports of illness and mortality in Germany, Britain, France, and the United States. In particular, Mr Gates fears a Spanish flu-like epidemic similar to the one that killed more than 65 million people in could decimate populations in a matter of months. Instead, the researchers found a very strong indication of spillover from domestic birds to wild birds. In both cases, the researchers found that the more susceptible age groups were exposed initially, as children, to viruses with a mismatched HA, and may suffer severe consequences similar to young adults faced with a mismatched virus in A molecular clock is a technique used in evolutionary biology to reconstruct family trees of organisms — or viruses — based on the number of genetic mutations accumulating over time. Secret of the Spanish flu epidemic uncovered. Worobey said the new perspective applies not only to the pandemic of , but might also explain patterns of seasonal flu mortality and the mysterious patterns of mortality when humans are infected by highly pathogenic avian-origin H5N1 and H7N9 viruses, commonly known as 'bird flu'. The results revealed a rapid, global replacement of the genes in the avian flu virus coinciding closely with a horse flu outbreak in the s that crippled the economy. Advertisement Share or comment on this article: The authors suggest that this likely was because many young adults born from about to were exposed during childhood to a putative H3N8 virus circulating in the population, which had surface proteins that were very different from those of the H1N1 virus. H5N1causes higher mortality rates in young people, and H7N9 causes higher mortality in the elderly. Earlier this year, Worobey and his collaborators published a study in the journal Nature providing the most comprehensive analysis to date of the evolutionary relationships of flu virus across different host species over time.