Figure 4: Systemic antibody response to RSV antigens. Serum and saliva samples were collected at 2 week intervals after mice were immunized with PBS, and DCNP via the i.n. route and with naked DR-FM2G DNA via the i.m. route. RSV specific antibody serum isotype IgG (A) and salivary isotype IgG (B) were determined by ELISA. Results are presented as an average of data from four groups in triplicate; error bars represent standard deviation. * Significantly different (P < 0.05) from PBS group; **, significantly different (P < 0.05) from PBS and DNA groups. P values were calculated by the Studentís t-test.