What is the advantage of using adeno-associated virus as a vector?

Using adeno-associated virus (AAV) as a vector has several advantages, one of which is its ability to evade a significant immune response. AAV is known for its non-pathogenic nature and has a favorable safety profile, which contributes to its utility in gene therapy. The fact that it does not elicit a strong immune response allows for repeated administration of the vector without the patient’s immune system attacking it. This is particularly beneficial in therapeutic contexts where sustained expression of the therapeutic gene is desired.

While AAV's relatively small capacity for DNA and random integration capabilities present limitations in certain applications, these factors do not outweigh the critical advantage of minimal immune recognition. Additionally, AAV's broad tropism – the ability to target various cell types – makes it a versatile choice for different therapeutic applications, rather than being limited to just targeting nerve cells.