La vaccination muqueuse cherche sa place parmi les nouvelles stratégies vaccinales.

Abstract

Une grande diversité d’approches vaccinales s’est développée ces dernières années et plusieurs nouveaux vaccins ont été mis sur le marché. La vaccination par voie muqueuse est une approche très étudiée. Le développement de vaccins contre les principales maladies diarrhéiques prévalentes au niveau mondial sera pris comme exemple pour dresser un bilan des promesses et des difficultés de cette approche.

Among the many vaccine approaches developed in the recent past, mucosal vaccination has been a major focus. Oral vaccination has been particularly studied for the development of vaccines against enteric pathogens. To induce a local immune response, protective antigens have to be targeted to the intestinal mucosa-associated lymphoid follicles. Two types of approaches are currently being developed: (1) live attenuated strains constructed by specific inactivation of virulence factors; (2) subunit vaccines using the purified protective antigens combined to a delivery system. Several vaccine candidates are promising (live attenuated strains for shigellosis; killed bacteria combined to the B subunit of cholera toxin, a potent mucosal adjuvant, for cholera). However, recent disappointing results (intussuception occuring following vaccination in children with a live rhesus-human reassortant rotavirus tetravalent vaccine; low immunogenicity of live bacterial attenuated strains tested in endemic areas...) emphasize some limitations that remain to be solved. Innovative strategies are being investigated : intranasal vaccination inducing both systemic and local immune responses at different mucosal sites, edible plant vaccines... The future remains full of promise.