VRC01 antibody prophylaxis blocked sensitive HIV-1 early, but infections with resistant virus rose as drug levels waned
- Follow-up analysis of two parallel Antibody Mediated Prevention trials of the CD4-binding-site antibody VRC01, tracking HIV-1 acquisition through the final study visit.
- Against viruses highly sensitive to VRC01, prophylaxis conferred substantial protection, consistent with blocking or clearing such infections.
- After dosing ended, antibody groups showed more diagnoses and resistance than placebo, including moderately sensitive or resistant viruses, suggesting waning levels let resistant strains establish; combinations of antibodies are likely needed.
💡 Points Based on the abstract
This reads as a classic exposure problem: a single bnAb only protects while concentrations stay above the neutralization threshold for a given strain, and as levels decay through the dosing interval, the trough becomes a selection window for less sensitive virus. Next steps are engineered Fc-extended antibodies for flatter exposure and combinations covering escape, with titers tied to protection.