1918 Influenza Pandemic and Highly Conserved Viruses with Two Receptor-Binding Variants

摘要

The Spanish influenza pandemic swept the globe inthe autumn and winter of 1918-19, and resulted in thedeaths of approximately 40 million people. Clinically, epi-demiologically, and pathologically, the disease was remark-ably uniform, which suggests that similar viruses werecausing disease around the world. To assess the homo-geneity of the 1918 pandemic influenza virus, partialhemagglutinin gene sequences have been determined forfive cases, including two newly identified samples fromLondon, United Kingdom. The strains show 98.9% to99.8% nucleotide sequence identity. One of the few differ-ences between the strains maps to the receptor-bindingsite of hemagglutinin, suggesting that two receptor-bindingconfigurations were co-circulating during the pandemic.The results suggest that in the early stages of an influenzaA pandemic, mutations that occur during replication do notbecome fixed so that a uniform "consensus" strain circu-lates for some time