Do they know this from a blood test that looks for antibodies? That is what I did for testing. The nasal swab amplication test looks for fragments in the air i

Do they know this from a blood test that looks for antibodies? That is what I did for testing. The nasal swab amplication test looks for fragments in the air intake filter, not actual infection. By the way, I had vaccines for polio measles tetanus and others. Being in decent physical health, my doctor confirmed I was not in a risk group which would benefit from the jab which was authorized for emergency use only. The risk/reward for my profile was not worth it.