Subunit Vaccine Candidates Engineered from the Central Conserved Region of the RSV G Protein Aimed for Parenteral or Mucosal Delivery

Respiratory syncytial virus (RSV) is a major pathogen causing severe upper and lower respiratory disease in infants and in elderly worldwide. According to WHO, an RSV vaccine is urgently needed. Here, we describe the design of various types of subunit vaccine concepts based on molecular engineering aimed to deliver RSV antigens. Gene segment encoding parts of the conserved central region of the RSV G protein (G2Na) were prepared for various expression and delivery formats: (1) prokaryotically expressed and purified G2Na alone or fused to different carrier proteins, one of them, namely, BBG2Na (Alum), has reached clinical trials in the elderly; (2) G protein-derived antigens surface displayed on lived vectors (non pathogenic bacteria) and (3) nucleic acid vectors.