D46cpΔM2-2 vaccine

D46cpΔM2-2 is a live-attenuated, recombinant respiratory syncytial virus (RSV) vaccine candidate developed by the National Institute of Allergy and Infectious Diseases (NIAID). It is designed for intranasal administration to infants and young children. The vaccine is attenuated through two primary modifications: the deletion of the M2-2 protein (a regulatory factor for viral RNA synthesis) and the inclusion of five cold-passage (cp) mutations in the nucleocapsid (N), fusion (F), and polymerase (L) genes. These mutations were originally derived from the cold-passaged RSV strain D46. In Phase I clinical trials (NCT02601612), the vaccine was found to be safe but overattenuated, resulting in low levels of infectivity and immunogenicity in both RSV-seropositive and RSV-seronegative children.

Other names

RSV LID delta M2-2respiratory syncytial virus LID delta M2-2