Dear Doctor, I believe I may have been exposed to HIV. Approximately 50 days after the potential exposure, I underwent an HIV test, and the result showed an index value of 0.59 S/CO units, indicating a non-reactive result (reference range: <0.90 S/CO units). Could you please clarify what the 0.59 S/CO unit value represents? Is there a risk that this value could increase over time, or does it suggest I am in a high-risk zone? Additionally, please advise if there are steps I can take to further reduce this value or ensure my safety. I would greatly appreciate a clear and detailed explanation.