Abstract: Series 106, Lecture 1
The Harvey Lectures Series 106 (2010—2011)
Lecture #1: Thursday, October 21, 2010 — Time and Location
Pandemic Influenza Viruses: Past and Future
Peter Palese, PhD
Horace W Goldsmith Professor and Chair
Department of Microbiology
Mount Sinai School of Medicine
New York, New York
There were three pandemic influenza viruses during the last century: the H1N1 virus of 1918, the H2N2 virus of 1957 and the 1968 H3N2 virus. By far the most virulent of these viruses was the one of 1918, which caused more than 50 million deaths worldwide. Advances in the laboratory using reverse genetics technologies, microarray and genome-wide siRNA analyses, as well as animal models, including the guinea pig transmission model, now allow us to study in detail the viral genes and the factors in the host and in the environment which are responsible for the virulence of these pandemic strains. For the reconstructed 1918 virus it was found that the hemagglutinin, the neuraminidase and the PB1-F2 genes are crucial in determining its extraordinary virulence. In contrast, the novel 2009 H1N1 pandemic strain is intrinsically much less virulent than the 1918 virus. Although this virus transmits well, it lacks the PB1-F2 gene, and it is a virus against which many people in the human population have partial (herd) immunity because of prior infections with seasonal H1N1 viruses. Unless the 2009 pandemic H1N1 virus acquires new genes and/or mutations in the future, it will remain a virus with relatively low virulence characteristics.