Squad, I am in the SIREN study which monitors levels of antibodies, and having been identified as having antibodies a year last July (never had a positive PCR test as was asymptomatic and the NHS was not regularly testing in the first outbreak), and I still have antibodies from that infection ( the blood tests discriminate between infection caused antibodies and vaccination induced antibodies). The research nurse at our site tells me that it is now that they are starting to see fewer people with antibodies.