On Apr. 14, 2003, researchers at Canada’s Michael Smith Genome Science Centre in Vancouver announced they had sequenced the 29,736-nucleotide genome of the SARS virus, an important step in the development of a potential treatment and vaccine.

Two days later, the U.S. Centers for Disease Control (CDC) published its own sequence, slightly shorter at 29,727 nucleotides but otherwise differing by only about ten base-pairs.