@Juspooped My SO got the J&J jab about a month ago and was sick for 5 days. At that time I was curious if I had an asymptomatic infection so I got an antibody test. Interestingly it came up IgM+/IgG-. The clinician said they had never seen that before. IgM+ indicates a recent exposure and IgG indicates long term antibodies present. According to the test results: "IgM is positive, but IgG is negative: The patient is having an early phase, active COVID-19 infection." We then both had PCR tests the following day which turned up negative. Assuming both tests were accurate it seems the only way for this to happen would be for me to have "caught" the spike protein from my SO.