Spanish flu: Encyclopedia II - Spanish flu - Recent research

Spanish flu - Recent research

In February 1998, The Molecular Pathology Division of the US Armed Forces Institute of Pathology (AFIP) recovered samples of the 1918 influenza from the frozen corpse of a Native Alaskan woman buried for nearly eight decades in permafrost near Brevig Mission, Alaska. Brevig Mission lost approximately eighty-five percent of its population to the Spanish flu in November, 1918. One of the four recovered samples contained viable genetic material of the 1918 virus. This sample provided scientists a first hand opportunity to study the virus, which was inactivated with guanidinium thiocyanate before transport. This sample and others found in AFIP archives allowed researchers to completely analyze the critical gene structures of the 1918 virus. "We have now identified three cases: the Brevig Mission case and two archival cases that represent the only known sources of genetic material of the 1918 influenza virus", said Jeffery K.Taubenberger, MD, PhD, chief of the institute's molecular pathology division and principal investigator on the project.

In September 2000, Noymer and Garenne published a study that poses an ætiological theory explaining the unusual W-shaped mortality age profile of the virus. This profile is characterized by a mode in the 25–34-year age group. Usually, influenza has a U-shaped profile, being most deadly to the young and the old. Additionally, after the pandemic the difference in life expectancy between men and women decreased (women had a historically longer life expectancy). Noymer and Garenne have causally linked these two anomalies to an interaction with tuberculosis. They point out that it is a predominantly male disease and that it is a disease of young adulthood rather than old age.

In October 2002, the Armed Forces Institute of Pathology teamed up with a microbiologist from the Mount Sinai School of Medicine in New York. Together, they started to reconstruct the Spanish Flu. In an experiment, published in October 2002, they were successful in creating a virus with two 1918 genes. This virus was much more deadly to mice than other constructs containing genes from contemporary influenza virus. The experiments were conducted under high biosafety conditions at a laboratory of the US Department of Agriculture in Athens, Georgia.

In the February 6, 2004, edition of Science magazine it was reported that two teams of researchers, one led by Sir John Skehel, director of the National Institute for Medical Research in London and another by Professor Ian Wilson of the Scripps Research Institute in San Diego had managed to synthesize the hemagglutinin protein responsible for the 1918 outbreak of Spanish Flu by piecing together DNA procured from a lung sample taken from the body of an Inuit woman buried in the Alaskan tundra and a number of preserved samples taken from American soldiers of the First World War. The two teams had analyzed the structure of the gene and discovered how subtle alterations to the shape of a protein molecule had allowed it to move from birds to humans with such devastating effects.

On October 5, 2005 researchers announced that the genetic sequence of the 1918 flu strain had been reconstructed using historic tissue samples ^[3]. The 2005 H5N1 bird flu strain spreading through Asia has some features of the 1918 strain but is so far not able to pass easily from human to human [4].

On October 21, 2005 AVI BioPharma Inc. announced that some combinations of antisense drugs appeared to reduce the rate of genetic replication of the 1918 Spanish flu virus in laboratory experiments. This testing most certainly would have occurred at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) or possibly CDC in an enhanced level 3 or level 4 biosafety lab [5]. Additional experiments showed that a single mismatch within the targeted region of the virus caused less than a 10 percent loss of activity of the drug. This raises the possibility that a single antisense drug could potentially shut down multiple virus subtypes, including possibly the H5N1 bird flu, even if a mutation occurred in these highly conserved regions [6]. AVI BioPharma and the USAMRIID have previously announced positive results from testing an antisense compound against the Ebola virus [7]. Other antisense compounds are in clinical tests for Hepatitis C virus (HCV) at the Dept. of Veterans Affairs [8].

Adapted from the Wikipedia article "Recent research", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki