Dear Doctor, Is it true that there are people who are immune to HIV/AIDS? After how long does one develop or show signs and symptoms of having acquired HIV? Eddie Dear Eddie, It is a fact. Some people are surprised to find themselves infected with HIV, though they had taken all precautions, whereas few may not get infected, in spite of being careless. There is a genetic mutation found in some people that makes them immune to being infected with HIV. This mutation called Delta 32 keeps a protein called CCR5 from rising to the surface of the T cells of the immune system. When CCR5 is not on the surface of the cell, HIV virus is not able to latch on it and infect the cell. This genetic mutation is very rare. Some scientists say that this mutation has been inherited from ancestors who survived the massive bubonic plague centuries ago. It is found in 1 per cent of Caucasians and is even rarer in native Americans, Asians and Africans. It has been shown that 1 per cent of descendants from North Europe are immune to HIV/AIDS. Even if a person has inherited the mutant gene resistant to HIV, from one parent, it is very useful in minimizing the risk of infection. The usual time for progression of the HIV infection to full blown AIDS(acquired immune deficiency syndrome), is usually 5 to 10 years. However it depends on several factors. The overall health status, life style factors, presence or absence of any sexually transmitted disease, awareness about HIV/AIDS and access to any good health facility, any intervention undertaken, are the factors which determine the progress of HIV positive state to AIDS. Individuals who start regular follow up and ARV drugs, early after being diagnosed as positive are known to have long and good quality lives, same as that for those suffering from any other chronic illness.