How a llama could hold the key to beating the coronavirus
- An antibody engineered from the animal’s immune system was found to neutralise the virus that causes Covid-19
- American and Belgian researchers hope the discovery may help protect humans from the deadly illness
A Belgian llama could hold the key to producing an antibody that neutralises the coronavirus that causes Covid-19.
More studies and clinical trials are needed to see if it can be used in humans to treat Covid-19, but the team of American and Belgian scientists who engineered the antibody said they were encouraged by their preliminary findings, which will be published in the journal Cell next week.
Jason McLellan, from the University of Texas at Austin and co-author of the study, described it as one of the “first antibodies known to neutralise Sars-CoV-2”, the official name for the virus.
“With antibody therapies, you're directly giving somebody the protective antibodies and so, immediately after treatment, they should be protected,” he wrote in a press release.
“The antibodies could also be used to treat somebody who is already sick to lessen the severity of the disease.”
The scientists have been working on coronaviruses – including severe acute respiratory syndrome (Sars) and Middle East respiratory syndrome (Mers) – for years.
In 2016 they injected the llama, named Winter, with Sars and Mers in the hope of developing a treatment for the diseases.
“I thought this would be a small side project,” said Dorien De Vlieger from Ghent University in Belgium, who helped to isolate antibodies against coronaviruses from the llamas.
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“Now the scientific impact of this project became bigger than I could ever expect. It's amazing how unpredictable viruses can be.”
A llama’s immune system produces two types of antibodies when it detects pathogens, one similar to human antibodies and one that is about a quarter of the size.
The antibodies produced by Winter were found to be effective in targeting the Sars virus’s spike protein, which allows it to bind to human cells.
This year they decided to test the antibodies Winter had produced during the Sars experiment to see if it could prove effective against Covid-19.
Although it did bind itself to the Sars-CoV-2 virus it did so “weakly”, so the team then linked two copies of the antibody together to make it bind more effectively.
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“That was exciting to me because I'd been working on this for years. But there wasn't a big need for a coronavirus treatment then. This was just basic research,” said Daniel Wrapp from the University of Texas, a co-author of the study.
The smaller type of antibodies produced by llamas, called single-domain antibodies or nanobodies, can be used in an inhaler, according to Wrapp.
“That makes them potentially really interesting as a drug for a respiratory pathogen because you're delivering it right to the site of infection,” said Wrapp.
The researchers are preparing for more trials with hamsters or primates to further test the antibody, before taking it to human trials.
The main subject of the study, Winter the llama, is now four years old and lives on a farm operated by Ghent University's Vlaams Institute for Biotechnologym which said it has around 130 other llamas and alpacas at the facility.
