Researchers have identified an antibody that is highly protective at low doses against the various types of SARS-CoV-2 virus that causes COVID-19. The findings, posted as pre-proof in the journal Immunity, could help develop new antibody-based therapies that are less likely to lose their potency when the virus mutates.
The researchers said the new antibody binds to a part of the virus, which varies slightly among different types, meaning resistance is unlikely to arise at this location. “Existing antibodies may work against some, but not all, types,” said senior author Michael S. Diamond, a professor at Washington University School of Medicine in St. Louis, US. “Viruses are likely to evolve over time and space. Broadly neutralizing, effective antibodies that work individually and can be combined to create new combinations will likely prevent resistance,” Diamond said. The SARS-CoV-2 virus uses a protein called spike to attach to and invade cells in the body’s respiratory tract.
Antibodies that prevent the spike protein from attaching to cells neutralize the virus and prevent disease. Many types have acquired mutations in their spike genes that allow them to evade some of the antibodies produced against the original strain, reducing the effectiveness of antibody-based therapeutics. To find neutralizing antibodies that worked against a variety of variants, the researchers immunized mice with a significant portion of the spike protein known as the receptor-binding domain (RBD). They then extracted antibody-producing cells and obtained 43 antibodies that recognize RBDs.