Llama antibodies could help in fight against Covid-19

Llama antibodies could help in fight against Covid-19

A group of researchers has identified a potential effective COVID-19 treatment, developed from antibodies found in a llama. The research was conducted by scientists at the University of Texas (UT) at Austin, the National Institutes of Health (NIH), both U.S., and Ghent University, Belgium. 

When llamas’ immune systems detect foreign invaders such as bacteria and viruses, these animals produce two types of antibodies: one that is similar to human antibodies and another that is about a quarter of the size. These smaller ones, called single-domain antibodies or nanobodies, can be nebulised and used in an inhaler.

The researchers linked two copies of a special kind of antibody produced by llamas to create a new antibody that binds tightly to a key protein on the coronavirus that causes COVID-19. This protein, called the spike protein, allows the virus to break into host cells. Initial tests indicate that the antibody blocks viruses that display this spike protein from infecting cells in culture.

“This is one of the first antibodies known to neutralize SARS-CoV-2,” said Jason McLellan, associate professor of molecular biosciences at UT Austin and co-senior author, referring to the virus that causes COVID-19.

The team is now preparing to conduct preclinical studies in animals such as hamsters or nonhuman primates, with the hopes of next testing in humans. The goal is to develop a treatment that would help people soon after infection with the virus.

“Vaccines have to be given a month or two before infection to provide protection,” McLellan said. “With antibody therapies, you’re directly giving somebody the protective antibodies and so, immediately after treatment, they should be protected. The antibodies could also be used to treat somebody who is already sick to lessen the severity of the disease.”

The team will report their findings on 5 May in the journal Cell.