Protective immunity elicited by vaccination with DNA encoding for a B cell and a T cell epitope of the A/PR/8/34 influenza virus.

Numerous reports have demonstrated that immunization with plasmids bearing influenza virus hemagglutinin (HA) or nucleoprotein (NP) genes elicits humoral and cellular protective responses. Herein we describe the generation of a plasmid (pVH-TB) encoding for a VH region of a self-Ig in which both the major B cell epitope HA150-159 and the immunodominant CD4 T cell epitope HA110-120 of HA of the A/PR/8/34 influenza virus were genetically inserted in the CDR2 and CDR3 loops, respectively. Our results demonstrate unequivocally that i.m. injection of pVH-TB plasmid in BALB/c mice elicited specific cellular and humoral immune responses able to protect against infection with lethal doses of A/PR/8/34 influenza virus.