A First in Human Trial to Evaluate Safety and Immunogenicity of a G Protein Based Recombinant Respiratory Syncytial Virus Vaccine in Healthy Adults 18-45 Years

Background: With enormous morbidity and mortality induced by respiratory syncytial virus (RSV) infection among infants and the elderly, vaccines against RSV infection are in huge market demand. Methods: We conducted a First-in-human (FIH), randomized, double-blind, placebo-controlled dose escalation study to evaluate the safety and immunogenicity response of the rRSV vaccine (BARS13) in healthy adults aged 18-45. A total of 60 eligible participants were randomized in a 4:1 ratio to receive one of four dose levels or vaccination regimens of BARS13 or placebo. Results: No serious adverse event (SAE) was experienced by any study participant. The geometric mean fold increase (GMFI) from baseline in all participants post-administration indicated that compared with single dose regimens, the IgG antibody level from baseline in participants received repeat dose regimens at Day 60 has increased over a 3-fold. Conclusions: BARS13 has a generally good safety and tolerability profile, and no significant difference in terms of adverse reaction severity or frequency has been observed between different dose groups. The immune response in repeat dose recipients shows more potential in further study and has guiding significance for the dose selection of subsequent studies.