A team of Israeli immunologists, epidemiologists and other researchers have successfully used the levels of antibody markers to predict the risk of Covid-19 infection. IGG antibodies for 608 healthy adults were monitored over 90 days. The 239 subsequent infections were then correlated.

https://www.timesofisrael.com/can-you-judge-your-covid-immunity-with-an-antibody-test-israeli-research-says-yes/