Two studies raised safety and assay concerns in viral vector-based gene therapy. First, work on AAV neutralization assays highlighted matrix effects that can distort antibody readouts, urging assay standardization for clinical gene-therapy screening. Second, researchers published findings on mutations in replication-defective HSV‑1–derived vectors that could pose safety considerations for herpesvirus-based platforms. Both reports stress the need for robust analytical methods and long-term follow-up to ensure vector integrity and patient safety in gene-therapy programs.