The present invention relates to isolation and characterization of a class of isolated novel viruses which is the precursor of the virus causing Severe Acute Respiratory Syndrome (SARS) in humans ("hSARS virus"). The precursor virus which is a SARS coronavirus-like virus ("SCoV-like virus") is identified to be morphologically and phylogenetically similar to hSARS virus. The present invention relates to a nucleotide sequence comprising the genomic sequence of the SCoV-like virus. The invention further relates to nucleotide sequences comprising a portion of the genomic sequence of the SCoV-like virus. The invention also relates to the deduced amino acid sequences of the SCoV-like virus. The invention further relates to the nucleic acids and peptides encoded by and/or derived from these sequences and their use in diagnostic methods and therapeutic methods. The invention further encompasses chimeric or recombinant viruses encoded by said nucleotide sequences and antibodies directed against polypeptides encoded by the nucleotide sequences. Furthermore, the invention relates to vaccine preparations comprising the SCoV-like virus, including recombinant and chimeric forms of said virus.