Over the last 30 days, 151 flocks have been confirmed to have avian flu, affecting more than 23 million birds, according to the Animal Planet Health Inspection Service part of the USDA. Dr. Paul Offit, of the FDA Vaccine Advisory Committee, says people could also become sick.

In the past three years, the U.S. Department of Agriculture (USDA) says about 150 million birds died across the country due to the virus. This month, the USDA granted a conditional license to Zoetis for its Avian Influenza Vaccine.