At this time it is unknown how long antibodies persist following infection and if the presence of antibodies confers protective immunity.
Click link to review FDA report:
Be aware that vaccines trigger antibodies to specific viral protein targets. For example, currently authorized COVID-19 mRNA vaccines induce antibodies to the spike protein and not to nucleocapsid proteins that are likely detected only after natural infections. Therefore, COVID-19 vaccinated people who have not had previous natural infection will receive a negative antibody test result if the antibody test does not detect the antibodies induced by the COVID-19 vaccine.
The FDA will continue to monitor the use of authorized SARS-CoV-2 antibody tests for purposes other than identifying people with an immune response to SARS-CoV-2 from a recent or prior infection.
WHAT THIS MEANS is that the FDA does not currently believe that this test can tell you whether the vaccine produced COVID antibodies.
A negative test result does not rule out the possibility of an infection with SARS-CoV-2. It has also been reported that certain patients with confirmed infection do not develop SARS-CoV-2 antibodies. Furthermore, waning of antibody titers has been reported in some individuals within a range of months after infection, a feature which has also been reported for other coronaviruses.