Scientists may have developed a new way of effectively neutralizing SARS-CoV-2 — the virus responsible for the COVID-19 pandemic, using a new class of antibodies.

In a study published in the journal Nature Communications, a team of researchers from Garvan Institute of Medical Research presented a new mechanism for dealing with the novel coronavirus. It utilizes a different class of antibodies capable of broadly neutralizing SARS-CoV-2, including the newer variants of concern.

According to the team, they conducted the study because the emerging variants of concerns are threatening to limit the effectiveness of the SARS-CoV-2 monoclonal antibodies and vaccines currently available to the public.

Since the five previously known classes of SARS-CoV-2 antibodies have varying effectiveness that wanes over time, they turned to a new class of antibodies that works by attaching themselves to the “partially hidden” part of the spike protein, making it hard for the virus to continue mutation.

The class 6 antibodies are said to be effective against the delta and omicron strains, even the newer variants of concern. They provided prophylactic and therapeutic protection against the viral challenge in mice, according to the scientists, who noted that their findings could help guide next-generation monoclonal antibody development and vaccine design.

"This is a new mechanism of action we're seeing with these class 6 antibodies," Daniel Christ, the director of the Antibody Therapeutics Lab at Garvan and corresponding author of the paper, said, as quoted by Medical Xpress.

"Our hypothesis is that they're so effective because the area we're targeting is close to the center of the spike's structure. When the antibody attaches there, it distorts the spike and rips it apart. It would be very difficult for the virus to adapt to that," he added.

The new antibody class was first discovered in small numbers in samples from patients in Sydney infected with the original variant of COVID-19.

Christ and his colleagues have since started working on evaluating the antibodies against the more recent strains, including the XBB.1.5 and XBF. Should they yield the same promising results, the medical community could see phase 1 clinical trials in 12 months.

"Almost all commercially available antibodies for COVID-19 don't work well anymore. Most are class 1 or 2, which refers to the fact that they bind to the most obvious spot on the spike protein—the ACE2 receptor binding site. They have downsides, including failure against new variants as they evolve," co-first author Dr. Jake Henry, a research assistant at Garvan, said.

Henry pointed out that the new mechanism could pave the way for new antiviral therapy that would introduce reliable “passive immunity” to at-risk individuals. He also said this could lead to more advanced treatments for other viruses.

"The exciting thing is that we describe a method we can use in the future to apply to other viruses — like flu or coronaviruses. This is a very quick way of identifying and isolating rare antibodies from recovering patients which leads to more effective treatment," Henry said.

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