I'm wondering if, after being exposed to HIV, the antibodies still show up in the body even four years later. Is there any possibility that they might vanish over time? And if they might disappear, would they still be detectable after a long period?

Yes, HIV antibodies can remain present in the human body for many years after exposure. In some cases, the antibodies may decrease over time but they are usually detectable even after a long period. It is important to note that HIV testing is still recommended for accurate diagnosis and monitoring of the infection.