1- Patients usually have no symptoms early after having acquired HIV; symptoms develop at later stages, when the virus has already multiplied to huge numbers (high viral load) and have invaded, even if in part, the immune system, which grows weaker. This makes the infection much more difficult to control, especially that HIV uses the cell's division mechanisms to multiply and spread.
2- Drug resistance: this occurs when HIV is no longer suppressed by HIV medicines that previously prevented the virus from multiplying. Drug resistance can develop as HIV multiplies in the body. During the viral multiplication process, the virus sometimes mutates (changes form) and makes variations of itself. Such variations that take place while a person is on ART can produce a new, drug-resistant generation of HIV. The drug-resistant HIV does not respond/is resistant to the HIV medicines that used to effectively suppress the multiplication of the original strain of HIV. Therefore, the person’s HIV continues to multiply. Once drug-resistant HIV sets in, it remains in the body and cannot be cleared easily. Drug resistance limits the number of HIV medicines available to include in an HIV regimen.
3- The available treatments (ART) can’t cure HIV, but by blocking HIV at different stages of the HIV life cycle, ART protects the immune system.