Updated on 11 June 2014
The deadly virus has caused around 774 deaths. The virus can be transmitted through coughing or sneezing and the infection can quickly spread from person to person. SARS spread through two dozen countries over a period of a few months before it was contained.
In addition to hiding the virus from the immune system, the SARS papain-like protease, or PLpro, enzyme also is responsible for snipping the viral polyprotein into individual proteins that are essential for viral replication. While some treatments are designed to prevent viral replication, researchers working on a vaccine must retain this function, he said.
"The goal in engineering a SARS virus that could be used as a vaccine is to create one that replicates in cells but is unable to fend off the body's immune response," he added. "We want enough viral particles to be generated to properly prime the immune system to fight off a true infection, but without the virus being able to cause illness in the vaccinated individual."