Antibodies taken from the blood of llamas could be used to help develop a new treatment for patients who are severely ill with COVID-19.
Laboratory tests have shown the antibodies can fight the coronavirus – and scientists hope to be able to push the breakthrough on into pre-clinical trials.
The antibodies – known as nanobodies due to their small size – could be engineered to neutralise the coronavirus.
The scientists found that the nanobodies can bind tightly to the spike protein of Sars-CoV-2 – the virus which causes COVID-19 – by blocking it from entering human cells and stopping any infection.
The work was carried out by a team from the Rosalind Franklin Institute, Oxford University, Diamond Light Source and Public Health England.
The immune system produces antibodies when it is being attacked, or in response to infections.
Llamas, camels and alpacas naturally produce quantities of small antibodies with a simpler structure that can be turned into nanobodies.
The researchers are now assessing results of antibodies taken from Fifi, a llama based at the University of Reading.
The findings show that Fifi’s immune system has produced different antibodies from those already identified, which will enable cocktails of nanobodies to be tested against the coronavirus.
It is hoped any future treatment could be used in a similar way to convalescent serum, which involves taking antibodies from blood donated from people who have recovered from an illness.
James Naismith, director of the Rosalind Franklin Institute and professor of structural biology at Oxford University, said: “These nanobodies have the potential to be used in a similar way to convalescent serum, effectively stopping progression of the virus in patients who are ill.
“We were able to combine one of the nanobodies with a human antibody and show the combination was even more powerful than either alone.”
The study was published in Nature Structural and Molecular Biology.