Are Ebola-fighting cows the first step toward human animals?

It’s not unusual for farms to have a herd of cows, unless those cows are a tiny bit human. One farm in Iowa has a herd of 50 black and white Holstein-Jersey crossbreeds that are just that. They have been genetically engineered with human DNA to produce a human immune system. These cows aren’t just mooing and chewing their cud, they also are producing antibodies against the Ebola virus—human antibodies.

Researchers hope the cows can be used to fight Ebola and other infectious diseases, such as various strains of influenza, Middle East Respiratory Syndrome (MERS), and hantavirus, a deadly virus that causes frequent outbreaks and killed three Yosemite Park campers two years ago.

“These animals produce very high levels of human antibody,” Eddie Sullivan, CEO and president of SAB Biotherapeutics, the company that developed the cows, told NBC News.

The genetically engineered and cloned cows were vaccinated against the Ebola virus, stimulating their immune system to produce antibodies. The method is similar to transfusing blood plasma from people who have survived Ebola into patients who are stricken with it. Researchers hope transfusing a patient with plasma from a survivor will jump-start the patient’s own immune response. Ebola survivor Dr. Kent Brantly has given more than a gallon of his blood plasma for such transfusions.

But one person, or even many people, cannot give enough blood to supply the need for vaccinations. Using cattle enables a much larger scale production of antibodies. Each cow can produce between 500 and 1,000 human doses per month, Sullivan said.

A few months after the cows were vaccinated, antibodies were taken from their blood plasma and shipped to the U.S. Army Medical Research Institute of Infectious Diseases (USAMRID). Scientists there injected the antibodies into mice that had been infected with Ebola.

“The first mouse studies have shown we can protect mice one day after they have been infected, but not two days after they have been infected, with a single dose,” Connie Schmaljohn, a senior research scientist at USAMRID, told NBC News. Now, the team is giving the mice a daily dose.

The next phase will test the antibodies in monkeys. If that is successful, the antibodies could soon be given to people, Schmaljohn said.

Using antibodies that are human has a significant advantage over techniques that use animal antibodies, which must first be treated with enzymes before being given to humans in order to prevent serum sickness, the researchers said.

But the researchers do not know if the method will be successful in fighting Ebola. It may be that human immune T-cells, which the cows do not produce, are necessary, in addition to antibodies, in fighting off the virus.

Even if the method works, it raises many ethical questions. Will technological advances soon enable scientists to make cows, and other animals, with even more human attributes? How much human DNA would an animal need to possess before being considered human and worthy of human rights?