Llama herd may be key to Covid-19 immunity

A herd of llamas in the English town of Reading may hold the key to treating patients severely ill with Covid-19, research suggests.

The woolly animals naturally produce a type of antibody called a nanobody, which can latch on to the spikes of the coronavirus that causes Covid-19.

Camels and alpacas can also produce nanobodies, which have a simpler structure than human antibodies.

Scientists from the Rosalind Franklin Institute at the University of Oxford, Diamond Light Source – the UK’s national synchrotron – and Public Health England have engineered llama antibodies to create an immune-boosting therapy.

Synchrotrons accelerate electrons to produce bright light that scientists use to study viruses and vaccines.

The therapy, details of which were published in the journal Nature Structural and Molecular Biology, could undergo clinical trials within months.

“With the llama’s antibodies we have keys that don’t quite fit,” said study author Prof James Naismith.

“They’ll go into the lock but won’t turn all the way round.

“So we take that key and use molecular biology to polish bits of it until we’ve cut a key that fits. These nanobodies have the potential to be used in a similar way to convalescent serum [from people who have recovered from Covid-19], 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. Combinations are particularly useful, since the virus has to change multiple things at the same time to escape.

“This is very hard for the virus to do. The nanobodies also have potential as a powerful diagnostic.”

Researchers are now screening antibodies from Fifi, a llama at the University of Reading, after she was immunised with harmless purified virus proteins. A similar study with immunised llamas took place in Buenos Aires, Argentina, last month.