Comparison of acute and long-term histopathologic scores after RSV inoculation. BALB/c (△) and C57BL/6 (●) mice were inoculated with sterile 10% EMEM (control) and were compared with RSV A2 infected BALB/c (□) and C57BL/6 (◆) mice. Serial formalin fixed lung samples were obtained between day 0 (+2 hours) and day 77 after inoculation. HPS scores are represented as means ± SEM. p < .05, by t-test when data normally distributed, or by Mann-Whitney Rank sum test when data were not normally distributed.