There has been a lot of news about how long you retain immunity after having the virus. 4 months is well within guidelines. There have been a few, but very few claims of reinfection. A positive antibody test is much better than a regular covid test for determining if someone is safe. A negative Covid test just tells you that at that moment the person did not have a detectable level of virus. Count the 48 hours prior to the test plus the 5 days and someone could interact with a large number of people. I am glad the USVI is using some common sense and sound medical advice.