I'm going to make this clear, cause I'm so sick of seeing it. Everyone is like, "oh you can get infected, the antibodies don't last very long". While there are rare scenarios, where reinfection can occur. The virus may be weird somehow and do something funky to the immune system, or the person may have a compromised immune system. There doesn't seem to be any indication of this though. Most viruses act differently in how long you retain high levels of antibodies. Just because you have low levels though doesn't mean you can't reproduce the antibodies. B cells produce antibodies. You end up with memory B cells. B cells express the antibody on their surface. They come in contact with the particular antigen, they will begin to produce antibodies again, very quickly raising your levels of antibodies. Everything isn't about B cells though, there is also T cells, and along with them memory T-cells. This thing that is spreading about how antibodies don't stay in your system very long or whatever, it is very misleading and most likely has nothing to do with whether reinfection will occur.