Photo/Illutration The Asahi Shimbun

Researchers developed an alpaca-derived antibody that could lead to a cheaper and more effective therapeutic option for the Omicron variant of the novel coronavirus.

The team from Kyoto University and other institutions said July 14 they created the tiny antibody based on a specialized antibody found in alpacas.

“We will proceed with animal experiments to develop a new type of inhalant,” said Akifumi Takaori, a professor of medicine at Kyoto University.

While antibodies are normally made up of proteins called heavy (H-) and light (L-) chains, alpacas and other Camelidae species can produce ones consisting exclusively of H-chains.

The separated edges of these antibodies are known as VHH antibodies, or nanobodies, which are smaller, easier to modify and more stable.

The team has been working on an antibody that can work against variants of the novel coronavirus based on alpaca’s VHH antibodies.

The team examined 20 million candidate antibodies from kept alpacas and selected six types that attach themselves strongly to spike proteins, which viruses use to invade cells.

One of them proved more effective than conventional treatment-purpose antibodies in stopping the Omicron variant from sneaking into cells. It also succeeded in inhibiting Alpha and other mutations.

An observation with a special electron microscope showed that the antibody is bound to deep grooves of spike proteins. Human antibodies are too large to fit these grooves, which are believed to rarely mutate.

The joint findings of Kyoto University, Osaka University, Yokohama City University, the University of Tokyo and biotechnology company Cognano Inc. were published in the online edition of the British scientific journal Communications Biology at (https://www.nature.com/articles/s42003-022-03630-3).