Figure 4.

RSV induced histopathology. Lung specimens were harvested on days 5 and 77 from groups of C57BL/6 and BALB/c mice inoculated with sterile medium (control) or RSV. Sections from control C57BL/6 and BALB/c mice above (4A and 4B, respectively), show rare, scattered, small lymphocytic infiltrates on day 5 after inoculation with medium, similar to sections of control mice harvested 77 days after (not shown). Acute and chronic inflammatory infiltrates, surrounding airways and vessels are demonstrated in RSV-inoculated mice of both strains, on days 5 and 77 after inoculation (4C to F).