You can say one person gets a virus that is worse than another person's virus because there are strain to strain variations. We also know that the immune system and the susceptible cells within the host are different.
差別可能來自於感染到的病毒不同，因為愛滋病毒分成好幾類；每個病人抵抗力的強弱也不一樣，所以有的能長期抗戰，有的快快束手就擒。此外，可能也有運氣的成份在內。