Evaluation of new adjuvants to enhance immune responses and the protective efficacy of a universal influenza vaccine

SANCHEZ, MARIA VICTORIA

Mendoza

Congreso; XXXVI Reunión Científica Anual Sociedad Biología de Cuyo; 2018

UNCUYO, UNSL

Influenza is a respiratory disease caused by influenza virus. This virus provokes annually a high impact in terms of morbidity and mortality worldwide. Most influenza vaccines induce antibodies that recognize surface viral proteins, hemagglutinin and neuraminidase. These antibodies are capable of neutralizing the virus. However, these proteins mutate constantly on antigenic sites which are recognized by antibodies. Therefore, the virus is able to evade the immune system. Every year the viral strains contained in the vaccine should be updated. The proposed strains are based on the prediction of the strains that will circulate that year. Nevertheless, antigenic mismatches between vaccine strains and circulating virus are frequent. As a result, the protection conferred by vaccines is often not optimal.New vaccines are under development in order to provide an improved immune response which confer protection against new strains. Our laboratory has been developing experimental influenza vaccines which contain a highly conserved antigen, the nucleoprotein (NP). It has been demonstrated that this antigen is able to induce cellular immune responses which confer protection against different strains of influenza. We formulated vaccines with a recombinant NP and new experimental adjuvants. The adjuvants which have been used, are molecules which are recognized by pattern recognition receptors and cytosolic DNA sensors. These compounds are able to activate innate immune response and lead to the stimulation of adaptive immune response.Our studies suggest that the combination of a recombinant NP and new adjuvants promotes an effective antigen-specific immune response which protects mice infected against influenza. In conclusion, the use of adjuvants in new influenza vaccines provides potential benefits to enhance immune responses which confer protection against influenza.