Research Shows Most People Have Ability to 'Neutralize' COVID-19

New research suggests that almost everybody’s immune system is capable of creating antibodies strong enough to neutralize SARS-CoV-2 if they’re exposed to the virus, but not everyone can make enough of them to be useful. However, if a vaccine is designed to target these particular antibodies, scientists think it will effectively boost immune response. 

After studying blood samples from 149 people who had recovered from COVID-19, researchers at Rockefeller University in New York were able to isolate three antibodies that could neutralize the SARS-CoV-2 virus, even at low concentrations. A virus is considered “neutralized” when it can no longer replicate itself. Most of the blood samples showed a poor ability to neutralize the virus. But closer inspection revealed they actually all had at least some of the cells necessary to create the three potent antibodies. 

"The antibody response to SARS-CoV-2 is very diverse across multiple individuals; some individuals develop a robust response, others only a weak or even undetectable response," Davide F. Robbiani, MD, PhD, head of the Laboratory of Immunology and Infectious Disease at the Institute for Research in Biomedicine, Switzerland, and one of the lead researchers of the Rockefeller study, tells Verywell. "Our most surprising discovery was that regardless of the potency of the response in a given individual, we were able to find antibodies nearly identical in composition in multiple convalescent (recovered) donors.”

A Little Immune Response Can Go a Long Way

The trick, researchers say, was first identifying the small percentage of people who were able to generate a strong neutralizing response to SARS-CoV-2. A successful immune response to a virus creates something called B cells—and a lot of them.

“The great thing about memory B cells is that if they re-engage with the [virus] that they’re specific for, they very rapidly differentiate into cells that can secrete massive amounts of antibodies,” Alice Cho, PhD, an immunology postdoctoral fellow at Rockefeller University, tells Verywell. “These antibodies can then be detected in the [blood] serum.” 

In other words, not only do these B cells create the antibodies necessary to protect against infection, they’re also quite easy to find. 

Once researchers knew what they were looking for, they were able to take a second look at the blood samples from people with poor virus neutralizing abilities. They found these samples also contained the same types of antibodies as the stronger samples, but in much lower concentrations. 

The long-term goal? Creating a vaccine to boost those concentrations. 

“If your [antibody concentrations] have dropped, you get a booster shot that will hopefully revive memory B cell responses,” Cho says. “This generates a high level of protective serum antibodies.”

In The Meantime, Blood Transfusions Can Boost Antibodies 

While vaccine research and development is still underway, physicians are already utilizing neutralizing antibodies from the blood of people who have recovered from COVID-19 to treat critically ill patients. The donated samples, called convalescent plasma, are given as blood transfusions to increase SARS-CoV2 antibodies in sick people. Mount Sinai Health System in New York City was the first in the U.S. to experiment with a process called therapeutic plasma exchange for this purpose.

“With convalescent plasma, the sooner a patient is given it, the better,” Makeda Robinson, MD, PhD, an infectious disease specialist at Stanford University, tells Verywell. “Most of the guidance from previous emerging viruses has been to try to give people convalescent plasma within the first two weeks after symptom onset, but I think there is likely still potential even after the manifestation of severe disease.” 

Robinson adds convalescent plasma could also be useful to prevent COVID-19. 

“It appears that neutralizing antibodies can make a bigger impact when given prior to symptoms of severe disease,” she says. “If you’re an essential worker or a healthcare worker, you could potentially receive a transfusion of antibodies before your high-risk interactions with patients. That way, you are giving your immune system a boost before you are exposed.”

How Long Will These Antibodies Last?

Previous research from Wuhan, China, the initial epicenter of COVID-19, found that neutralizing antibodies in recovered patients may only last in the body for three months—not exactly offering long-term protection. But the Rockefeller University researchers say it’s normal for antibodies to wane over time, and that a vaccine should extend the life of these antibodies.

“I don’t think a short-lived antibody response is a sign that the immune system is failing in response to the coronavirus,” Cho says. “Our immune system just responds differently to different infections. Some may elicit potent antibody responses that persist for a lifetime, and some do not. This is not ideal in terms of protection against COVID-19, but it’s nothing that we cannot overcome with an effective vaccine.”

Robinson explains immunity from a natural infection can differ from immunity conferred from a vaccine in important ways.

“A natural infection leads to a broader response, which can be more heterogeneous” she says. “Vaccinations which target specific parts of the virus typically lead to a more homogeneous immune response that may be a bit more narrow and potent.” 

Many SARS-CoV-2 vaccines in development are targeting the spike protein found on the virus, which is believed to be the section that binds to host cells in humans. The three potent antibodies discovered by the Rockefeller University team, for example, bind to three different sections on this spike. Still, Robbiani says a vaccine is just one piece of the puzzle when it comes to boosting our antibodies. 

“Preliminary experimentation in humans is promising, but a SARS-CoV-2 vaccine does not exist at the moment,” he says. “Let’s not forget that vaccines are only one approach against coronavirus.”

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