Llama antibodies can create a vaccine against COVID-19. The first experiments began in 2016

The researchers linked two copies of a special kind of antibody produced by llamas to create new antibodies,

which bind strongly to a key proteincoronavirus that causes COVID-19. This protein, called the spike protein, allows the virus to enter host cells. Initial tests show that antibodies block the viruses that this protein demonstrates from infecting cells in culture.

The team is currently preparing forpreclinical animal studies, such as hamsters or primates, with the hope of the next human testing. The goal is to develop a treatment that would help people soon after becoming infected with the virus.

“This is one of the first antibodies that, likeknown to neutralize SARS-CoV-2. Vaccines based on it should be administered a month or two before infection in order to provide protection. With antibody therapy, you directly give someone protective antibodies, and so they should be protected immediately after treatment. Antibodies can also be used to treat someone who is already sick to reduce the severity of the disease. ”

Jason McLellan, Assistant Professor of Molecular Life Sciences at UT Austin

When the immune system of llamas detects alieninvaders, such as bacteria and viruses, these animals (both camels and alpacas) produce two types of antibodies: one is similar to human antibodies, and the other is much smaller. These small antibodies are called single domain antibodies or nanobodies; they can be nebulized and used in an inhaler.

Lama Winter is 4 years old and he still lives ona farm in rural Belgium along with 130 other llamas and alpacas. His participation in the experiment occurred in 2016, when he was about 9 months old, and the researchers studied two early coronaviruses: SARS-CoV-1 and MERS-CoV. In a process similar to how people were vaccinated to immunize against a virus, he was given stabilized proteins from these viruses for about six weeks.

“The fact that they can be nebulized in an inhaler makes them potentially interesting as a medicine for a respiratory pathogen because you deliver it directly to the site of infection."

Daniel Vrapp, graduate student at the McLellan Laboratory

Researchers then collected a blood sample and isolated antibodies that bound to each version of the protein. One of them showed a real result.

The team developed new antibodies thatpromise to treat the current SARS-CoV-2 by linking two copies of the llama antibody that worked against the earlier SARS virus. They demonstrated that the new antibody neutralizes viruses that detect proteins from SARS-CoV-2 in cell cultures. Scientists were able to complete this study and publish it in the best journal in a matter of weeks thanks to many years of work on coronaviruses.

“It was exciting to me because Iworked on this for years. But then there was not much need for treatment with coronavirus. It was just basic research. Now this may have some translational consequences. ”

Daniel Vrapp, graduate student at the McLellan Laboratory

The first antibodies that the group identified inThe initial tests of SARS-CoV-1 and MERS-CoV included one called VHH-72, which is closely related to the pointed proteins on SARS-CoV-1. At the same time, he prevented infection of cells with a pseudotyped virus - a virus that cannot infect humans and which was genetically engineered to demonstrate copies of the SARS-CoV-1 spike protein on its surface from infection of cells.

When SARS-CoV-2 appeared and caused a pandemicCOVID-19, the team wondered if the antibody they detected for SARS-CoV-1 would also be effective against its relative. They found that it also binds to the peak protein SARS-CoV-2, albeit weakly. The engineering that they did for more efficient binding included the binding of two copies of VHH-72, which, as they then showed, would neutralize the pseudotyped virus possessing spike proteins from SARS-CoV-2. This is the first known antibody that neutralizes both SARS-CoV-1 and SARS-CoV-2.