Scientists have identified a new pair of antibodies that could fend off multiple COVID-19 variants. Found in people who successfully recovered from the illness, these antibodies attach to a part of the COVID-19 virus that doesn’t appear to mutate, potentially allowing them to last longer in the body.
Vaccinations for viruses like COVID-19 work by introducing bits of genetic code, or mRNA, to the body. The mRNA contains instructions that direct the body to produce a small, harmless piece of the target virus. With this piece of the virus in the body, the immune system learns to manufacture antibodies that work against the virus, thus preparing it for “real-life” exposure to the disease.
But the virus behind COVID-19 is infamous for evolving quickly. As the virus morphs, the antibodies required to fight it must change, too, which means the vaccine itself must change. As a result, scientists are constantly working to play vaccine catch-up, producing inoculations for a particular variant months after it’s begun to spread.
The antibodies discovered by researchers at Stanford University, Rockefeller University, and Seattle’s Fred Hutchinson Cancer Center meanwhile appear to work in such a way as to maintain their hold on the virus, even as it adapts. According to a paper published this month in Science Translational Medicine, two different types of antibodies work in tandem to tackle the SARS-CoV-2 spike protein by attaching to parts of the virus that do not mutate. This means the antibodies can maintain their hold on the spike protein long enough to neutralize the virus in the body.
CoV2-biRN5 and CoV2-biRN7 each attach to different parts of the SARS-CoV-2 spike protein, preventing it from infecting human cells.
Credit: Christopher O. Barnes/Adonis Rubio/Stanford University
The researchers identified these antibodies within samples donated by COVID-19 survivors. Collectively, the pair are called CoV2-biRNs, and they deliver a one-two punch that disables the virus altogether. One antibody, CoV2-biRN5, works by attaching to the spike protein’s N-terminal domain, or NTD, which itself doesn’t change. Then, the antibody called CoV2-biRN7 can attach to the spike protein’s receptor-binding domain, or RBD, thus preventing the protein from infecting healthy human cells.
In an in-vitro test (i.e. in a petri dish), the researchers saw that both CoV2-biRN antibodies retained their ability to neutralize multiple variants of the COVID-19 virus. The antibodies also reduced viral load in the lungs of mice exposed to a single Omicron variant. Together, these findings suggest that the CoV2-biRN pairing could be the key to stopping COVID-19’s many evolutions in their tracks—though extensive additional research will be necessary before the antibodies can be used in a vaccine.
“Viruses constantly evolve to maintain the ability to infect the population,” senior study author and Stanford University assistant biology professor Christopher Barnes said. “To counter this, the antibodies we develop must continuously evolve as well to remain effective.”