Codagenix is moving its rational virus design platform forward with a new Phase I trial of its live attenuated respiratory syncytial virus (RSV) vaccine in children.

Codagenix has dosed the first subject in a Phase I study (NCT04919109) designed to test the safety and immunogenicity of CodaVax-RSV, the company announced Wednesday. The trial will vaccinate 51 healthy children in the spring to early autumn of 2023 and follow participants through the 2023–2024 RSV season.

The Phase I study will test CodaVax-RSV or placebo in 18 children aged 2–5 followed by 33 children aged 6 months to 2 years. Primary outcomes focus on safety, while the secondary endpoint explores neutralising antibody levels.

CodaVax-RSV, which has US Food and Drug Administration (FDA) fast track designation, is part of Codagenix’s live-attenuated vaccine platform that also targets Covid-19 and influenza. Codagenix also plans to initiate a Phase II trial of the same vaccine during the 2023-2024 RSV season.

As Codagenix begins dosing in its new Phase I trial, the race to develop RSV vaccines is quickly heating up. New investment and a recent uptick in pediatric and elderly RSV cases has placed a renewed spotlight on the respiratory virus.

Correction: A previous version of this article incorrectly stated that CodaVax-RSV is an mRNA-based vaccine. The headline and article have been updated to reflect that it is a live-attenuated vaccine.