What were the clinical features and outcomes of H1N1 infection?

Clinically, the symptoms of H1N1 influenza were similar to those of seasonal influenza and included fever, cough, sore throat, body aches, headache, chills, and fatigue. Some patients also experienced diarrhea and vomiting. Most infections were mild, but severe cases could lead to pneumonia, acute respiratory distress syndrome (ARDS), and death, particularly in individuals with underlying health conditions, pregnant women, and the immunocompromised.