Methods: The levels of the specific antibody in the serum of SARS patients in varied period, the healthy and feverous patients without SARS were detected by the Indirect ELISA and the Double antigen sandwich method. 方法:采用间接法和双抗原夹心法分别检测健康人、发热非SARS患者、不同时期的SARS患者血清中的特异性抗体水平。