Does U=U apply during breastfeeding? An urgent research priority

Area of Science:

• Virology
• Public Health
• Infectious Diseases

Background:

• The question of whether undetectable HIV viral load prevents transmission during breastfeeding (U=U) remains critical for HIV prevention strategies.
• Current evidence suggests low, but not zero, risk of breastfeeding transmission with maternal viral suppression, limited by older ART regimens and sparse breast milk data.

Purpose of the Study:

• To evaluate the applicability of the undetectable equals untransmittable (U=U) principle to breastfeeding in women living with HIV.
• To address the urgent need for rigorous prospective studies to clarify breastfeeding transmission risks.

Main Methods:

• Propose studies using modern integrase inhibitor-based antiretroviral therapy (ART).
• Incorporate frequent plasma and breast milk viral load monitoring.
• Include comprehensive infant follow-up and rights-based counseling.

Main Results:

• Existing data indicate exceedingly low breastfeeding transmission risk with maternal viral suppression.
• Limitations include infrequent viral load monitoring, older ART regimens, and incomplete follow-up.

Conclusions:

• Urgent need for prospective studies to definitively answer if U=U applies during breastfeeding.
• Women with HIV must be supported in making autonomous, informed infant feeding choices based on evolving evidence and shared decision-making.