The deadly bird flu outbreak infected and killed a number of chickens and turkeys in the United States. Now, to fight the disease, the United States Agriculture Department (USDA) has decided to use a vaccine.

Until now, the department has not allowed the farmers to vaccinate their flocks. According to the department, the process of vaccination could prompt wider import bans on the United States poultry and eggs in the $5.7 billion export market. Inoculations produce antibodies could make it difficult to find if a bird actually had the virus.

On Tuesday, while talking to Reuters, the agency's chief veterinarian, John Clifford, said, “Once a vaccine is ready - something likely to take months - circumstances might prompt approving it for targeted use in areas with a high number of cases”.

The H5N2 is a subtype of the species Influenzavirus A. It is capable of infecting a wide variety of birds, including chickens, turkeys, ducks, falcons, and ostriches. The strain appeared in the country at the start of the year. Currently, the deadly strain is present in about 12 states. According to reports, it is the most wide-reaching outbreak in the United States in last 30 years.

The USDA has been trying to develop a vaccine that could protect birds like chickens and turkeys from the deadly strain of flu. On Monday, an Iowa egg farm reported the outbreak. The outbreak has triggered tougher measures on farms to keep infections at bay.

James Sumner, president of the USA Poultry & Egg Export Council, said that the outbreak has been making things difficult for the country. Export markets like China, South Korea and South Africa have already instituted total bans on United States poultry costing about $430 million a year.

Steve Olson, executive director of the Minnesota Turkey Growers Association, said that vaccine is necessary to treat birds. According to him, he would like to see a vaccine available to farmers.