Correct - there was a long-term memory T cell response. However, see sentance immediately preceeding the one you quoted - basically SARS-CoV IgG antibodies ("Ig

Correct - there was a long-term memory T cell response. However, see sentance immediately preceeding the one you quoted - basically SARS-CoV IgG antibodies ("IgG Ab" below) were totally absent 6 years after infection. So, antibodies against SARS are not produced long-term, unlike many other types of viral infections, and unlike the desired mechanism of most vaccines. "Six years postinfection, specific IgG Ab to SARS-CoV became undetectable in 21 of the 23 former patients. No SARS-CoV Ag-specific memory B cell response was detected in either 23 former SARS patients or 22 close contacts of SARS patients." here is HTML version of article https://www.jimmunol.org/content/186/12/7264.long https://www.jimmunol.org/content/186/12/7264.long (DOI 10.4049/jimmunol.0903490)