CCL5 and Airway obstruction: During the acute phase in both mouse strains, airway obstruction (AO) peaked on day 5 and strongly correlated with histopathologic scores (HPS), BAL concentrations of RANTES, IFN-γ, MIP-1α and MIG, and RSV loads measured by both plaque assay in BAL samples and RLT-PCR in lung supernatants (Additional file 1).