Background/Objectives: Respiratory syncytial virus (RSV) causes severe infection in neonates and infants. However, a suitable RSV vaccine for children is yet to be approved. The development of KD-409 is focused on creating an effective and safe RSV vaccine for newborns and children. The safety and efficacy of the RSV FG chimeric protein KD-409 were evaluated in several rodent models. Methods/Results: The effect of vaccine-induced antibody transfer was verified in a guinea pig model. Next, the exacerbation of infection was evaluated in a BALB/c mouse model of passive immunity designed to mimic the vaccination of pregnant women. KD-409 did not exacerbate infection when administered with alum, unlike pre-F with alum. Our active immunization model of BALB/c mice, which involved stimulating vaccination with a pediatric vaccine, suggested that KD-409 with alum was less likely to exacerbate inflammation than FI-RSV or pre-F with alum. The efficacy was evaluated in a cotton rat model, in which KD-409 demonstrated greater protection against infection than pre-F without adjuvant, the only currently approved formulation for immunizing pregnant women. Conclusions: KD-409 eliminated concerns about vaccineenhanced disease in pediatric vaccination and demonstrated superior efficacy to current vaccines in rodent models. The safety in mice during passive and active immunization, and efficacy in cotton rats demonstrate the high potential of KD-409 as a safe and effective next-generation RSV vaccine candidate that can cover the neonatal-to-pediatric age range.
Loading....