Medians of Antibody titers of different groups of mice after second and third immunizations after intranasal vaccination (Exp1). To determine the fold change of titers, the serum samples of two different time points i.e. after second (bleed1) and third immunizations (bleed2) were analyzed. A minimum of four fold change of titers has been observed in IgG, IgG1 while a two to fourfold increase of titers has been observed in IgG2a. IgA response after the second immunization was very low but increased fourfold after third immunization. Bleed1 denotes titers from blood collected after second immunization, Bleed2 denotes titers from blood collected after third immunization.