Center for Disease Control is worried a pandemic may be nearing. If the avian flu evolves and becomes more virulent, the flu can become more widespread and more dangerous. Of the 400 people that have been infected with H5N1, nearly 60% of them have died. Those most at risk are poultry farmers, travelers, and people who may consume uncooked meat from infected birds. Some symptoms include a high fever,headaches, diarrhea and trouble breathing. A vaccine is being developed that can be deployed if the avian flu becomes more pathogenic and spreads from animals to humans more easily.