On Aug. 17, 2020, Scientisfic American reported that Costa Rican scientists at the Clodomiro Picado Institute have inoculated six horses with engineered proteins of the SARS-CoV-2 virus. After four rounds of inoculations, the horses produced the desired level of antibodies. At this point, their blood was extracted, and the red blood cells were separated from the plasma and returned to the horses.

To test the efficacy of the equine antibodies, vials were shipped to NCBID where tests showed the virus was neutralized. The results of the research were expected to be published.