BY: Samantha Bartlett

Scientists in the United States and Belgium are working together to develop antibody therapy against COVID-19 using llama antibodies. A collaboration between University of Texas in Austin, the National Institutes of Health and the University of Ghent in Belgium, the team has been working on developing antibody treatment since 2016 for SARS and MERS with the introduction of the COVID-19 virus, they refocused their efforts on the new virus. The treatment would be similar to a vaccine, but would provide instant immunity that would wear off in 1-2 months. While the antibody treatment will not replace a vaccine when one is developed, the researchers hope to prevent severe illness in people that are already infected and possibly to provide prophylactic protection to at-risk populations such as health care workers.

Llamas are ideal for this research because they have two types of antibodies compared to one type found in the human body. One of the antibodies is normal sized like a human antibody, but the other is smaller by about 25%. It is the smaller antibody, called a nanobody, that seems better able to recognized the COVID-19 virus and to attack the spike proteins the virus uses to attach itself to the host cell. By attacking the spike proteins, the nanobodies should be able to stop infection by the virus. The nanobodies are also easier to manipulate for treatment and easier to mass produce. 

The research llama, Winter, has been injected with a protein found on the surface of the COVID-19 virus and has created antibodies to that protein. The researchers isolated the antibodies and have shown effectiveness in neutralizing the COVID-19 virus in vitro. The next step is determining if the antibodies are effective in vivo and then human trials. 

Llamas have been used in the past to develop treatments for HIV and influenza. A drug to treat thrombotic thrombocytopenic purpura, called Caplacizumab, is on the market that was developed from llama antibodies.