The immunogenicity, protective efficacy and safety of BBG2Na, a subunit respiratory syncytial virus (RSV) vaccine candidate, against RSV-B.
Respiratory syncytial virus (RSV) is divided into subgroups A and B, based primarily on variation within the G glycoprotein. A safe vaccine that protects against both would be the ideal. BBG2Na is a recombinant subunit RSV vaccine candidate derived in part from the G protein of RSV-A. Interestingly, BBG2Na formulated in alum protected against RSV-B challenge at early time points following vaccination in mice. Over 6 months, however, BBG2Na-induced immunogenicity and protective efficacy progressively diminished, such that few animals were considered protected at the end. To study the safety of BBG2Na relative to RSV-B challenge, we established a novel enhanced immunopathology mouse model. We confirmed that RSV-B challenge of formalin-inactivated RSV-A (FI-RSV-A)-immunized BALB/c mice results in enhanced pulmonary pathology. Therefore, this phenomenon is neither subgroup-specific nor dependent on a previously incriminated Th epitope in the RSV-A G protein. In stark contrast, BBG2Na did not induce any signs of enhanced pulmonary pathology. In conclusion, our data indicate that BBG2Na, formulated in alum, induces safe and protective immune responses against RSV-B challenge in mice. However, the duration of protective immunity will probably be insufficient to prevent RSV-B infection for the duration of the RSV epidemic season.
Power
Ultan F
UF
Centre d'Immunologie Pierre Fabre, 74164, Saint-Julien-en-Genevois, France. ultan.power@pierre-fabre.com
Plotnicky
Hélène
H
Blaecke
Aline
A
Nguyen
Thien Ngoc
TN
D000818:Animals; D016516:CD4-CD8 Ratio; D002469:Cell Separation; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D007114:Immunization; D007115:Immunization Schedule; D008168:Lung / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D022261:Respiratory Syncytial Virus Vaccines / Q000096:biosynthesis / Q000276:immunology*; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology*
C472186:BBG2Na vaccine; D016207:Cytokines; D022261:Respiratory Syncytial Virus Vaccines