What is a key consideration when choosing a vector for somatic gene therapy?

• A. Color of vector
• B. Safety and delivery efficiency, including tropism, immunogenicity, and whether the vector is integrating or non-integrating
• C. Only cost considerations
• D. Only plasmid size matters

Answer: (B)

Choosing a vector for somatic gene therapy is about balancing safety with how effectively the gene can be delivered to the right cells. The most important factors are tropism, which determines which tissues or cell types the vector prefers; immunogenicity, which reflects how strongly the host immune system may react to the vector and influence safety and the need for repeated dosing; and whether the vector integrates into the genome or remains non-integrating, which affects the durability of expression and the risk of insertional mutagenesis. A vector with the right tropism can reach the target cells; low immunogenicity minimizes adverse immune responses; and the integration profile manages the trade-off between long-term expression and genomic safety. Color of the vector has no bearing on therapeutic value. Cost and plasmid size matter for practicality, but they don’t override the core needs of targeting, safety, and expression duration.