“According to reality, those exposed to SARS in 2003 have immunity to SARS COVID-19.”
When getting COVID vaccination:
To test that possibility, Wang’s team compared neutralizing antibodies from the vaccinated SARS survivors—all health care workers in Singapore—with those from SARS patients who had not received a COVID-19 vaccine. Wang’s team also analyzed antibodies in three other groups: unvaccinated people who currently had COVID-19, along with vaccinated people who had recovered from SARS-CoV-2 or had never been infected with that virus.
The vaccinated SARS survivors were the only cohort whose antibodies neutralized 10 different coronaviruses, according to a new assay Wang’s team developed that tests the antibodies’ ability to block binding between ACE2 and the receptor-binding domains (RBDs) of different spikes. And the levels of the neutralizing antibodies were relatively high against each one. “It’s superinteresting,” says Neil King, a biomedical engineer at the University of Washington, Seattle, who is also working on pancoronavirus vaccines. “It may lead people to reprioritize their efforts.”
From the report: "Singapore study shows that SARS-CoV-2-specific T cells are present in all recovered COVID-19 patients. These T cells were also found in all subjects who recovered from SARS 17 years ago..."
https://scitechdaily.com/scientists-uncover-evidence-that-a-level-of-pre-existing-covid-19-sars-cov-2-immunity-is-present-in-the-general-population/