Why cant people with aids foght out the infection?

They can fight the infection but not the disease

Because aids is a power disease, u can get it from anything but commonly its through sexual intercourse or oral and most people who get it CANT fight it because it has already reached their blood stream with the disease of aids. Aids CANT be cured purely but can be TREATED through special procedures depending on HOW u got aids in the first place. It can even be kissing another person who may be sick or already has aids and just transferred it to u.

 Hope this helps.