Anti-SARS monoclonal antibodies

A method of preparing a chimeric antibody chain comprising:

• introducing an expression vector which comprises a nucleic acid encoding a constant region domain of a human light or heavy chain and a nucleic acid encoding a light chain variable region G18-light as set forth in SEQ ID No. 32 or a heavy chain-variable region G18-heavy as set forth in SEQ ID No. 23 into a suitable host cell;
• growing the host cell under conditions promoting expression of the chimeric antibody chain;
• and
• recovering the chimeric antibody chain.

A method of preparing a humanized antibody chain comprising:

• providing a nucleic acid comprising a light chain variable region G18-light as set forth in SEQ ID No. 32 or a heavy chain variable region G18-heavy as set forth in SEQ ID No. 23);
• modifying said nucleic acid such that at least one but fewer than about 30 of the amino acid residues of said variable region has been changed and/or deleted to reduce immunogenicity in humans without disrupting antigen binding;
• introducing said nucleic acid into a suitable host cell;
• growing the host cell under conditions promoting expression of the humanized antibody chain;
• and
• recovering the humanized antibody chain.