What usually signals the end of the acute stage of HIV infection?

The end of the acute stage of HIV infection is typically signaled by a rebound in CD4 count. During the acute stage, which occurs shortly after the initial infection, the virus replicates rapidly, leading to a significant decline in CD4 T-cell counts as the immune system responds to the presence of the virus. Following this initial phase of rapid viral replication, the immune system begins to mount an effective response, and CD4 T-cells start to recover.

This rebound in CD4 count is crucial as it indicates that the person's immune system is beginning to regain function and control over the virus, even though the virus may still be present in the body. It marks the transition from the acute phase to what is known as the clinical latency stage, where the virus is less active but still established.

Other factors such as decreases in viral load and rises in antibody production are also important in managing HIV, but they do not necessarily mark the end of the acute stage. A decrease in viral load occurs later as the immune response improves, while antibody production reflects the body's response to infection, which may not directly correlate with changes in CD4 counts during the transition from acute to chronic infection. Symptoms may vary in appearance and severity, but they do not serve as