attenuated Streptococcus pneumoniae strain I

Attenuated Streptococcus pneumoniae strain I (also known as SpnA1) is a live, genetically modified, virulence-attenuated strain of *Streptococcus pneumoniae* (serotype 6B) under clinical investigation by the Liverpool School of Tropical Medicine (LSTM) and collaborators, including University College London. It is engineered with mutations in the *fhs* (formyltetrahydrofolate synthetase) and *piaA* (iron transporter) genes, which affect bacterial metabolism and iron uptake, thereby reducing systemic virulence while retaining the ability to colonize the human nasopharynx. Administered intranasally, the live attenuated bacterium acts as an immunogen to stimulate local mucosal and systemic immune responses, protecting against subsequent colonization and infection by wild-type *Streptococcus pneumoniae* (pneumococcal disease).

Other names

Δfhs/piaAΔfhs/piaattenuated Streptococcus pneumoniae strain 1attenuated S. pneumoniae strain Iattenuated S. pneumoniae strain 1