Australian medical researchers have found an unlikely hero in a pair of alpacas they hope will help them develop a prevention and treatment for COVID-19.
The nameless duo have been immunised with safe, non-infectious virus fragments, to trigger their rare immune response.
The camelid species, as well as some sharks like the Wobbegong, produce an extra, miniscule type of antibody which enable them to fight the 'spiky' coronavirus in ways human antibodies can't.
Alpacas were the easy choice of the two, Associate Professor Wai-Hong Tham told AAP.
"We're interested in these nanobodies because they're really stable, can fit into things that other bigger antibodies can't, and they're very sticky to the protein target, which is a good thing to have in a treatment option," she told AAP.
The joint head of infectious disease at Melbourne's Walter Eliza Hall Institute, Ms Tham is leading the project which will attempt to recreate and manipulate the nanobodies in a lab.
First, researchers will need to identify which of the alpaca's millions of nanobodies - which are ten times smaller than regular antibodies - best inhibit the virus.
Then, they'll have to make them more closely resemble human antibodies, so our immune systems don't kill them off.
But Ms Tham says those objectives are achievable, and any treatment would be easily scalable too.
"The fact that there is already an approved nanobody drug for blood clotting shows that you really can deploy nanobodies well."
The team is currently designing the nanobodies to be used both as a prevention and treatment for the virus.
"In populations that may not mount a very good immune response to the vaccine for a variety of reasons, we could deploy the antibody-based therapies then, because there we're directly giving you the antibodies that work," Ms Tham said.
Immuno-compromised people and those in aged care are the best candidates for that use of nanobodies, but they could also be used in treatment of mild COVID cases.
The project is part of a larger search for suitable antibodies by Australian researchers, and would need to be among the top prospects for research to continue.
"If all goes well and they're potent and they're safe, then we'll be looking at clinical trials next year," Ms Tham said.
As for the alpacas, the team says their involvement is harmless, and they'll enjoy long and happy lives in their East Gippsland home.
Australian Associated Press