Defective 5′‑Leader HIV Genomes Drive Most Persistent Viremia on ART

A new blood test that tells intact viral RNA from broken copies could reduce needless treatment changes and ease transmission concerns.

Overview

The Nature Communications paper published June 8, 2026, reports that roughly 95% of detectable plasma HIV‑1 RNA in the studied group came from defective genomes with mutations or deletions in the 5′‑leader region.
Researchers examined samples from 52 people with non‑suppressible viremia and developed CLAWS, a digital PCR assay that distinguishes intact 5′‑leader RNA from defective 5′‑leader RNA without full sequencing.
Defective 5′‑leader proviruses cannot infect new cells but still release viral RNA or particles, so detectable plasma RNA in these cases does not equal infectious virus or clear transmission risk.
Clinically, using CLAWS to identify defective RNA could spare patients extra drugs, tests, or delays for surgeries and trial enrollment and provide reassurance to people on long‑term ART.
The study cohort was small and mostly older men from the U.S., Canada and Denmark, so the authors call for larger and more diverse validation and prospective clinical studies before changing guidelines.