IL6 and tuberculosis: The replication-deficient phenotype of the TB/FLU-04L was proven by the absence of virus isolation from the nasal swabs taken on days 2, 4, and 6 p.i. Relative to the pre-immunization baseline, intranasal immunization with TB/FLU-04L resulted in higher IL6 levels in nasal secretions collected 24 and 48 h after immunization (Figure S1).