CNN.com – Researchers reconstruct 1918 virus: “Researchers reconstruct 1918 virus”. Scientists have made from scratch the Spanish flu virus that killed as many as 50 million people in 1918, the first time an infectious agent behind a historic pandemic has ever been reconstructed. Why did they do it? Researchers say it may help them better understand — and develop defenses against — the threat of a future worldwide epidemic from bird flu. The researchers also refined their focus on one gene, the HA gene, that encodes the hemagglutinin surface protein that help the virus attach to cells and multiply. The 1918 virus is deadly with the HA gene, but when the gene was replaced, it was not virulent, Tumpey said. The virus particles are being stored at the CDC, and there are no plans to send samples off campus, said Dr. Julie Gerberding, the agency’s director.