I’m participating in a clinical trial of the Pfizer vaccine. It is a messenger RNA that encodes production of the spike protein, which your body then produces antibodies against. You are not exposed to actual virus or the complete viral genome. I have my second and final shot in three weeks. it is a randomized double blind trial with half of the participants receiving a placebo. A few weeks after the second shot I will run my own antibody test and determine my vaccination status. I was negative for antibodies in a test at my primary care office a few days before enrolling in the study. Several other studies are underway in the US involving a total of ca. 100,000 participants.