Before revision:  While the quality of antibody testing  and the likelihood of even attaining COVID-19 immunity continue to be researched, we address the issues involved in providing tamper-proof and privacy-preserving certification , both for COVID-19 immunity and in general .
After revision:  While the quality of antibody testing , the availability of vaccines, and the likelihood of even attaining COVID-19 immunity continue to be researched, we address the issues involved in providing tamper-proof and privacy-preserving certification , both for COVID-19 immunity and in general .