Did they get the SARS vaccine? They were living there...
the only sars vaccine trials I know of were run on mice:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3371787/
8. Xiong S, Wang YF, Zhang MY, Liu XJ, Zhang CH, Liu SS, et al. Immunogenicity of SARS inactivated vaccine in BALB/c mice.
10. Chou TH, Wang S, Sakhatskyy PV, Mboudoudjeck I, Lawrence JM, Huang S, et al. Epitope mapping and biological function analysis of antibodies produced by immunization of mice
11. Qu D, Zheng B, Yao X, Guan Y, Yuan ZH, Zhong NS, et al. Intranasal immunization with inactivated SARS-CoV (SARS-associated coronavirus) induced local and serum antibodies in mice.
25. Yang ZY, Kong WP, Huang Y, Roberts A, Murphy BR, Subbarao K, et al. A DNA vaccine induces SARS coronavirus neutralization and protective immunity in mice.