There is absolutely no way one can claim "strong immune response in 2020 for the original 2003 SARS virus" unless it was actually verified by reinfection. I am

There is absolutely no way one can claim "strong immune response in 2020 for the original 2003 SARS virus" unless it was actually verified by reinfection. I am aware of the article claiming that there is some kind cellular reaction to SARS, but first of all, it might be not enough at all to protect from reinfection, and secondly, it might be case of well documented cross-immunity from some common cold viruses.