SAb Biotherapeutics of Sioux Falls, South Dakota, is pursuing an extension of previous research in genetically modifying dairy cows so that certain immune cells carry the DNA that allows people to make Covid-19 antibodies. Cows become giant bioreactor antibody factories. They have more blood engineered to synthesize human versions of the proteins and their blood can also contain twice as many antibodies per milliliter as human blood than smaller animals.
Source: Science, June 8, 2020. Link. Instead of making just one antibody variety, the cows fashion polyclonal antibodies, a range of the molecules that recognize several parts of the virus. “That’s the natural way that our bodies fight disease,” Sullivan says. This diversity may make the cow’s proteins more powerful than monoclonal antibodies, he says, and they may remain effective even if a virus mutates.