Severe acute respiratory syndrome; vaccine on the way

摘要

In November 2002, a new disease-severe acute respiratory syndrome, or SARS-first emerged in Guangdong Province, China. Subsequently, it spread to more than 30 countries worldwide. The causative agent was identified to be a previously unknown member of the coronaviridae family, and was named SARS coronavirus ( SARS-CoV) . SARS coronavirus is a large, enveloped, positive-sense RNA virus. The genome is about 30 kb, which is predicted to contain 14 functional open reading frames ( ORFs) . Two large 5 ' -terminal ORFs (1a and 1b) encode the polymerases that are required for viral RNA synthesis. The remaining twelve ORFs encode four structural proteins [ spike protein (S), envelope protein (E), membrane protein (M) and nucleocapsid protein (N) ] and eight accessory proteins. Though the SARS-CoV genome is clear, a great deal more work will be required to develop an efficient vaccine and effective drugs. Neutralizing antibodies were detectable in the convalescent sera of SARS patients, and sera from recovered patients could be used to treat newly infected individuals. The data suggest that protective humoral immunity is achievable and that vaccines can be developed for prevention of SARS. In this article, we review and discuss progress towards development of a SARS vaccine.