Figure 3. Lung viral titers of mice infected with wild-type (WT) or H274Y mutant isolates of pH1N1.

Mice were infected intranasally with 5×10⁵ PFUs of either WT pH1N1 (A/Québec/147023/2009) or oseltamivir-resistant H274Y mutant (A/Québec/147365/2009) isolate. Three to four mice per group were sacrificed on days 1, 3, 6 and 9 for determination of lung viral titers, which were reported as TCID₅₀ per gram of lung.