The Genesis of a Pandemic Influenza Virus
Charles Chuck Russell2005, Cell
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Abstract
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Pandemic influenza viruses, particularly the H5N1 strain, pose a significant public health concern due to their potential for human-to-human transmission. Recent studies by Taubenberger et al. (2005) and Tumpey et al. (2005) have revealed crucial genomic similarities between the 1918 Spanish influenza virus and avian strains, suggesting two primary pathways for the emergence of pandemic strains: gene reassortment involving co-infection with human and avian viruses, or direct mutation of avian influenza viruses. Understanding the molecular basis of these processes is critical for predicting and preventing future influenza pandemics.
Key takeaways
- Meanwhile, Tumpey et al. (2005) reporting in Science show that the reconstructed 1918 Spanish influenza virus kills mice faster than any other influenza virus so far tested.
- In the twentieth century, three influenza viruses emerged that caused major pandemics: the 1918 Spanish flu virus, the 1957 Asian flu virus, and the 1968 Hong Kong flu virus.
- Unexpectedly, the sequences of the polymerase proteins (PA, PB1, and PB2) of the 1918 virus and subsequent human viruses differ by only ten amino acids from the avian influenza virus consensus sequence.
- They show that the reconstructed 1918 virus kills mice faster than any previously characterized influenza virus.
- The substantial number of human cases caused by the H5N1 strain of avian influenza virus over the past two years (118 reported cases and 61 deaths), some clusters of probable human-to-human transmission, and the similarity to 1918 pandemic influenza virus all suggest that the only remaining trait for H5N1 to acquire to become a pandemic virus is efficient human transmissibility.
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