Targeting O1a-Antigen for E. coli Vaccine Development

🧬 Targeting O1a-Antigen for E. coli Vaccine Development 🧫

A May 2024 Pfizer Vaccine R&D study explores the development of a long-chain O1a CRM197 lattice glycoconjugate as a promising vaccine candidate against Escherichia coli serotype O1, a major cause of neonatal meningitis and bloodstream infections. The O1a-antigen, a component of the bacterial lipopolysaccharides (LPS), is structurally distinct from other subtypes, like O1b and O1c, which makes it more virulent. This structural difference in the monosaccharide composition plays an important role in its pathogenicity.
Key Findings:
🔹 The O1a glycoconjugate triggered strong immune responses in preclinical models.
🔹 It provided >90% protection against lethal challenges regardless of the presence of K1-capsule.
🔹 Since the O1a type is found in about 80% of invasive E. coli ST95 cases, this vaccine could be a key part of future protection against serious infections.
This long-chain O1a CRM197 lattice glycoconjugate shows promise as a component of a multivalent vaccine to prevent invasive E. coli infections.

Lipopolysaccharides (LPS) can vary structurally even within the same bacterial species, affecting a strain’s antigenicity. Precise characterization of LPS or Polysaccharides (PS) is crucial for effective vaccine development.

For more info, check out this link on PS preparation for vaccines by LPS-BioSciences.

DOI: 10.1128/spectrum.04213-23