How long do the effects of gene therapy based on adeno-associated virus last? A plain language summary

This is a summary of a review article. The article was about how long the effects of one type of gene therapy may last. Review articles summarize many published scientific articles. The original review article was published in the journal Molecular Therapy in March 2022. Genes are inside cells and carry the information that determines a person's genetic makeup and traits (for example, their features or characteristics) that they get (inherit) from their parents. People living with genetic conditions have genes that do not work (function) like they should. Gene therapies have been developed for people living with serious rare health conditions. They aim to treat the cause of the condition instead of just managing symptoms. Gene therapy is designed to add a functioning copy of the gene into a person's cells. The functioning copy of the gene is inserted into cells by vectors. Vectors are designed to act as vehicles to deliver the functioning copy of the gene into a person's cells. Often, these vectors are based on a virus because viruses are good at getting into the body. Vectors use the outer shell of the virus, but the viral genes are replaced with a therapeutic gene. Some vectors are modeled on the adeno-associated virus (AAV). This article is about AAV-based gene therapy and how long its treatment effects can last (durability or duration of treatment effect). Further research is needed to understand what can affect how long the benefits of gene therapy will last. Currently, AAV-based gene therapy can only be given once. An important aspect of successful gene therapy is its durability. Research is ongoing to find ways to increase the durability of gene therapy.