phase 4 trial

Immunogenicity and Safety of Fractional 17DD Yellow Fever Vaccine Doses in Young Children: Evidence from a Phase 4 Randomised Trial in Uganda and Broader Context

Fractional doses (one-fifth and one-half) of 17DD yellow fever vaccine demonstrate non-inferior immunogenicity and comparable safety to full doses in children aged 9–23 months, supporting dose-sparing strategies during vaccine shortages.