The present invention relates to an isolated novel virus causing Severe Acute Respiratory Syndrome (SARS) in humans ("hSARS virus"). The hSARS virus is identified to be morphologically and phylogenetically similar to known member of Coronaviridae. The present invention provides the complete genomic sequence of the hSARS virus. Furthermore, the invention provides the nucleic acids and peptides encoded by and/or derived from the hSARS virus and their use in diagnostic methods and therapeutic methods, including vaccines. In addition, the invention provides chimeric or recombinant viruses encoded by said nucleotide sequences and antibodies immunospecific to the polypeptides encoded by the nucleotide sequences.