A new analysis of antibody-mediated prevention trials finds that the broadly neutralizing antibody VRC01 provides strong initial protection against HIV-1 acquisition but breakthrough infections can occur after treatment stops. Researchers reviewed data from HVTN 704 and HPTN 085, where participants received infusions for 80 weeks. The findings, published in Science Translational Medicine, suggest that the durability of protection declines and that viral escape or resistant strains can still drive post-cessation infections. The results point to the potential need for combination antibody strategies to sustain coverage and suppress breakthrough risk. For the prevention pipeline, the work adds practical evidence on how long protection may last and helps shape the next generation of AMP trial designs and antibody pairings.