One of the challenges of fighting COVID-19 is that vaccines and booster shots, while effective in protecting most people against severe infections, are often ineffective in those with weakened immune systems. In August, however, researchers at Tel Aviv University in Israel claimed to have identified a pair of antibodies that neutralize every known strain of the SARS-CoV-2 virus. In the process, they may have taken a step toward altogether obviating the need for booster shots to fight new strains as they evolve.
According to an August article published in the journal Communications Biology, a pair of antibodies — TAU-1109 and TAU-2310 — could play a crucial role in halting the infection process. If you picture the SARS-CoV-2 virus as a sphere surrounded by spikes, then the antibodies are Y-shaped molecules which fight that sphere and spikes at targeted points. TAU-1109 and TAU-2310 seem to choose an area of the viral spike sphere that is very different from where most of the antibodies choose to go.
This made them less effective at fighting the original SARS-CoV-2 virus, but more so when it comes to the pervasive strains circulating today — including the omicron strain.
"According to our findings, the effectiveness of the first antibody, TAU-1109, in neutralizing the Omicron strain is 92%, and in neutralizing the Delta strain, 90%," Dr. Natalia Freund of Tel Aviv University, the lead researcher behind the study, explained in a press statement. "The second antibody, TAU-2310, neutralizes the Omicron variant with an efficacy of 84%, and the Delta variant with an efficacy of 97%."
In the process, they may have taken a step toward altogether obviating the need for booster shots to fight new strains as they evolve.
The researchers argue that technologies developed from their discovery could render repeated booster vaccinations unnecessary and offer a means of strengthening immunity within at-risk populations. At the same time, as the authors of the study point out, there is an ongoing need for research into antibodies that human beings produce as they encounter the SARS-CoV-2 virus.
"As new variants of SARS-CoV-2 continue to emerge, it is important to assess the cross-neutralizing capabilities of antibodies naturally elicited during wild type SARS-CoV-2 infection," the authors explain.
Scientists and medical experts said the study was performed with rigor. Dr. Russell Medford, Chairman of the Center for Global Health Innovation and Global Health Crisis Coordination Center, told Salon by email that this was "a well-done study with appropriate conclusions drawn from the study results." Dr. William Haseltine, a biologist renowned for his work in confronting the HIV/AIDS epidemic, told Salon that it "seems like a credible study, one of many such describing neutralizing antibodies and mappng them to their binding sites."
Dr. Monica Gandhi, an infectious disease doctor and professor of medicine at the University of California–San Francisco, helped place the new study in a broader immunological context. Antibodies are the part of the immune system that deals with the lesser threats to our health, she clarified.
"To put it simply, antibodies protect us from mild infections but cellular immunity (T and B cells) protect us from severe disease," Gandhi wrote to Salon. "The variants have tended to have a high degree of mutation in the spike protein, which binds to the host cell receptor (called the ACE2 receptor). This study verifies that monoclonal antibodies directed towards the ACE2 binding site are more affected by viral mutations than monoclonal antibodies that bind to regions outside the receptor binding site."
In a sense, this new development means that the part of the immune system which deals with lesser threats can be harnessed, as scientists realize those two aforementioned antibodies have been fighting the SARS-CoV-2 virus in a distinctive way.
"Simply put, this means that antibodies the body generates directed against other parts of the virus beyond the site that binds to our host cell receptor work better against variants," Gandhi explained.
Dr. Georges Benjamin, executive director of the American Public Health Association, concluded that the study points the development of disease-fighting technology in a promising direction. At the same time, more research needs to be done.
"We do need a lot more research to better understand biological markers that can be used to diagnose and help with prognosis for vaccinated and unvaccinated people who get infected with SARS-CoV--2," Benjamin explained.
