Figure 1. Infants infected with influenza virus exhibit significant increases in disease in the lung.
Infant or adult African Green monkeys were infected with IAV by the combined i.t. and i.n. routes. Three infants received 1×109 EID50 and one infant received 1×108 EID50 of PR8. Adults (4) each received 5×109 EID50. A. Weight over time for infant and adult animals. Closed symbols are individual animals, open symbol represents the average for the group. B. Average change in weight for infants over the course of the assay. Weight change over 10 days in a group of age-matched historical control animals is shown for comparison. C. On d14 p.i. animals were euthanized and lungs assessed for disease. Disease scores are based on a summation of scores assigned for interstitial and alveolar inflammatory cell infiltration and edema, pneumocyte hyperplasia, and bronchial degeneration and necrosis. Each parameter was scored on a scale of 0 to 4 with higher numbers associated with increased severity. Significance testing was performed using a Mann-Whitney test. * p=0.029. D. Representative sections of affected areas from the lungs of infant and adult animals (2.5X, upper panels and 40X, lower panels).