The U.S. Department of Agriculture reported 13 new outbreaks of the H5N2 bird flu in Minnesota.

With the new outbreaks, the total number of farms infected has risen to 44. Over 2.5 million turkeys and 3.8 egg-laying hens have been killed by the virus that has hit 16 states in the U.S.

Federal health researchers are in the process of creating and testing human and avian vaccines against the bird flu, according to Minneapolis Star Tribune.

In Wisconsin this week, agriculture regulators reported that there had been to new outbreaks. One infected 800,000 hens making it the second-largest incident in the U.S. since the original outbreak of bird flu this year.

At this time, there have been no human fatalities or illnesses reported linked to the H5N2 outbreak. The U.S. Centers for Disease Control believe that the risk is low among humans. But they are still attempting to create a human vaccine in the comfort of preparedness, said Dr. Alicia Fry of the National Center for Immunization and Respiratory Diseases.

“We are really at the beginning of this,” Fry said. “We are cautiously optimistic we will not see any human cases, but there is a possibility we may.”

The World Health Organization reported that there were 784 human infections and 429 deaths since the 2003 H5N1 strain that mainly hit Asia.

Although the new H5N2 strain is related to the previous one, state public health veterinarian, Joni Scheftel, does not see any risk for human infection.

“This virus gives no indications that it would do that. Even the bad H5 viruses that have been identified around the world … do not have a propensity to be transmitted person to person.”

Scheftel said that there is not concern that the virus would mutate at this time to a transmissible disease. The only concern is that it could infect somebody with a susceptibility to infection due to a specific genetic profile.

Health officials in Minnesota, the state most directly affected by the outbreak, is monitoring farmworkers for infections. They have already had 48 workers agree to take Tamiflu, the recommended preventative treatment.

“We’ve had zero human cases even among people who have had intense contact with sick birds,” Scheftel said. “That’s very different from the other viruses we’ve been alarmed about in the past. … Any H5 has the potential to infect people, so we’re acting out of an abundance of caution.”

Researchers believe that a human vaccine is important because of the expectation that the H5N2 could be around for multiple years now that it has made its home in North America.