Elite-Responder Antibodies Neutralize Coronavirus
It’s now clear that nearly everyone who recovers from COVID-19 produces antibodies that specifically target SARS-CoV-2, the novel coronavirus that causes the infection, stated Dr. Francis S. Collins, the Director of the U.S. NIH.
Antibodies are blood proteins that the immune system makes to neutralize viruses or other foreign invaders.
On June 30, 2020, Dr. Collins continued to explain in his weekly blog ‘just how well do those particular antibodies neutralize the virus to fight off the infection and help someone recover from COVID-19.’
Fortunately, most people get better when infected with SARS-CoV-2, but should the typical antibody response take the credit?
A new NIH-funded study of people who recovered from COVID-19 offers some essential insight.
This study, published in the journal Nature on June 18, 2020, shows that most people, in fact, do produce antibodies that can effectively neutralize SARS-CoV-2.
But there is a catch: 99 percent of the study’s participants didn’t make enough neutralizing antibodies to mount an ideal immune response.
The good news is that when researchers looked at individuals who mounted a strong immune response, they were able to identify 3 antibodies that were extremely effective at neutralizing SARS-CoV-2.
By mass-producing copies of these antibodies as so-called monoclonal antibodies, the researchers can now better evaluate their potential as treatments to help people who don’t make strongly neutralizing antibodies, or not enough of them.
The immune system doesn’t make just one antibody to thwart an invader; it makes a whole family of antibodies.
But not all antibodies in that family are created equal.
They can vary widely in where they latch onto a virus-like SARS-CoV-2, and that determines how effective each will be at blocking it from infecting human cells.
That’s one reason why people respond differently to infections such as COVID-19.
More intriguing to these researchers were the results from individuals that showed an unusually strong ability to neutralize SARS-CoV-2.
Among these “elite responders” and other individuals, the researchers identified 40 different antibodies that could neutralize SARS-CoV-2.
But again, not all antibodies are created equal.
Three neutralized the virus even when present at extremely low levels, and they now will be studied further as possible monoclonal antibodies.
The team determined that those strongly neutralizing antibodies bind 3 distinct sites on the receptor-binding domain (RBD) of the coronavirus spike protein.
This portion of the virus is important because it allows SARS-CoV-2 to bind and infect human cells.
Importantly, when the researchers looked more closely at plasma samples with poor neutralizing ability, they found that they also contained those RBD-binding antibodies, just not in very large numbers.
While this research showed that there’s a lot of variability in immune responses to SARS-CoV-2, it appears that most of us are inherently capable of producing antibodies to neutralize this devastating virus.
That finding brings more reason for hope, concluded Dr. Collins’s blog.
Dr. Collins is the 16th Director of the NIH, originally sworn in on August 17, 2009.
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