Ca/04-specific serum antibody responses following vaccination with live-attenuated influenza virus (LAIV) or whole-inactivated influenza virus (WIV). Pigs were bled the day of boosting (pre-boost), prior to challenge (post-boost), and 5 days post-challenge for evaluating Ca/04-specific A) hemagglutination inhibition (HI) titers, B) virus serum neutralization (SN) titers, and C) IgG and D) IgA levels to whole virus. HI and SN titers were log2 converted and reported as the geometric mean ± SEM. Negative HI reactions are at the minimal level of detection (10), denoted by the dotted line. Antibody isotype data is expressed as the mean ± SEM optical density (OD) for 10 pigs per treatment group. A one-way analysis of variance with a Tukey’s post-test was used for statistical analysis and p-values <0.05 are indicated with connecting bars.