Polyclonal breast milk-derived secretory IgA confers broad antiviral protection against multiple respiratory viruses.

Polyclonal breast milk-derived secretory IgA provides complete protection against influenza A in mice, reducing viral burden and improving lung health.

• Why it matters: Respiratory viruses enter primarily through mucosal surfaces, and current passive immunization methods face limitations in accessibility and effectiveness at these sites. Addressing these gaps could improve protection for vulnerable populations.
• What they did: Researchers tested LCTG-001, a polyclonal secretory IgA from pooled human breast milk, demonstrating broad antiviral activity against respiratory viruses, including influenza A subtypes and H5N1, through in vitro and in vivo experiments.
• The result: Intranasal administration of LCTG-001 in murine models prevented morbidity and mortality, suggesting breast milk-derived secretory IgA as a scalable, mucosa-targeted passive immunization strategy for endemic and emerging respiratory viruses.