PEOPLE infected with the original strain of the virus that causes COVID-19 early in the pandemic produced a consistent antibody response, making two main groups of antibodies to bind to the spike protein on the virus’s outer surface. However, those antibodies don’t bind well to newer variants, a study of the University of Illinois (UI) found.
The researchers studied published papers about COVID-19 patients for data about the sequence of the antibodies they produced. They focused on antibodies against the spike protein, the part of the virus that binds to receptors on human cells to infect them. The spike protein is the target of most vaccines.
They found that many antibody sequences converged into two main groups, indicating a consistent human immune response to the virus.
The researchers studied the convergent antibodies’ ability to bind to several variants and found that they no longer bound to some. The finding has implications for the ability of new variants to reinfect people who contracted earlier versions of the virus, as well as for the continuing efficacy of vaccines and the design of possible vaccine boosters, said study leader Nicholas Wu, a UI professor of biochemistry.
“Even though this antibody response is very common with the original strain, it doesn’t really interact with variants,” said Wu. “That, of course, raises the concern of the virus evolving to escape the body’s main antibody response. Some antibodies should still be effective -- the body makes antibodies to many parts of the virus, not only the spike protein -- but the particular groups of antibodies that we saw in this study will not be as effective.”
The researchers said they would like to conduct similar studies characterizing antibody responses to Delta and other variants, to see whether they also produce a convergent response and how it differs from the original strain.
The findings, posted on UI’s website on Friday, have been published in the journal Nature Communications. SOURCE: Xinhua