Prime-boost strategy against pertussis in mice: benefits and mechanisms

ZURITA, MARIA EUGENIA; GAILLARD, M. EMILIA; BOTTERO, DANIELA; HOZBOR, DANIELA

Bruselas

Simposio; 12th International Symposium on Bordetella; 2019

Differences between current pertussis vaccines could explain, at least in part, the worrying pertussis epidemiological situation described in countries that only use acellular vaccine (aP) in their calendar. While classical whole cell vaccine (wP) induces relative long-term protection and promotes Th1/Th17 responses; acellular vaccine induces Th2 profile and their induced immunity wanes faster than wP. We have already identified and characterized a vaccine candidate based on outer membrane vesicles (OMVs) that has been shown to be safe and able to induce protection in mice, with a mixed Th1/Th17/Th2 profile and a robust antibody response. Since prime-boost vaccine strategies could enhance cellular and also humoral immunity, we evaluated the performance of heterologous prime-boost strategies, using the OMVs based vaccine to prime mice and commercial aP vaccine as booster. One month after the last immunization, we evaluated the humoral and cell-mediated immune responses induced. For comparative purpose, a schedule consisting in two dose, one with aP and the second with OMVs (aP-OMVs) was also analyzed. Treatments with two doses of aP or non-vaccinated were used as controls. We detected significantly higher levels of Total IgG against B. pertussis in sera of mice primed with OMV based vaccine (294,3±37,1) in comparison with other treatments (p