Evaluation of heterologous prime-boost immunization strategy against Bordetella pertussis using a novel outer membrane vesicle based vaccine and commercial acellular vaccine.

MARIA EMILA GAILLARD; DANIELA BOTTERO; GRISELDA MORENO; MARTIN RUMBO; EUGENIA ZURITA; MARTINEZ SABATER DAVID

Mar del Plata

Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC) LXIV Reunión Anual de la Sociedad Argentina de Inmunología (SAI) XLVIII Reunión Anual de la Sociedad Argentina de Farmacología Experimental (SAFE) VII Reunión Anual de la Sociedad; 2016

Pertussis remains an important health problem in many countries even in those with high vaccination coverage. From 1950s-1990s this disease was controlled by use of whole cell pertussis (wP) vaccines. Later in 2000s these vaccines were replaced in developed countries by acellular pertussis (aP) vaccines (purified components of Bordetella pertussis (Bp) absorbed to alum). The new aP vaccines, although safer, are not as effective as the wP vaccine and this has been attributed to: 1) escape form protective immunity, 2) waning immunity or 3) a failure of the aP vaccine to induced protective cellular immune responses. Under this context, we have developed a new vaccine candidate based on outer membrane vesicles (OMVs) derived from Bp which is capable of inducing a more robust immune response than commercial aP vaccines with a Th2/Th1/Th17 cellular profile. Here we evaluated the immunogenicity of a heterologous prime-boost regimen using OMV-base and aP vaccines. For comparison purposes homologous vaccination regimens with OMV based vaccine and aP were also performed. For all cases, the induced humoral and cell-mediated immune responses were evaluated. A robust total IgG antibodies with a high IgG2a/IgG1 ratio were detected in sera of mice primed with OMV based vaccine, suggesting that OMVs skewed the immune response to a Th1 profile. Spleen cells from immunized mice were isolated and stimulated in vitro with B. pertussis antigens. Interestingly the obtained results showed that the priming with OMV vaccine induce a strong Th1/Th17 response with high values of INF-ϒ (2100 ±350 pg/ml p