Tables indicate the pigs in the PASSIV‐VAC and NAIVE groups. Numbers in the top indicate the days post‐contact (DPC) for each group. Gray boxes indicate the samples that tested positive by RRT‐PCR for IAV, and the numbers within the gray boxes indicate the CT value of the samples that were used for HA sequencing. The days where all pigs tested negative were excluded for simplicity (R: replicate, S: seeder)