We have previously reported that lung cellular bioenergetics (cellular respiration and ATP) increased in 4–10 week-old BALB/c mice infected with respiratory syncytial virus (RSV). This study examined the kinetics and changes in cellular bioenergetics in ≤2-week-old C57BL/6 mice following RSV infection. Mice (5–14 days old) were inoculated intranasally with RSV and the lungs were examined on days 1–10 post-infection. Histopathology and electron microscopy revealed preserved pneumocyte architectures and organelles. Increased lung cellular bioenergetics was noted from days 1–10 post-infection. Cellular GSH remained unchanged. These results indicate that the increased lung cellular respiration (measured by mitochondrial O₂ consumption) and ATP following RSV infection is independent of either age or genetic background of the host.