Covid's original strain anti-bodies don't bind well to newer variants, finds study

New York: People infected with the original strain of the SARS-CoV2 virus that caused Covid-19 early in the pandemic outbreak produced a consistent antibody response, with two major groups of antibodies binding to the spike protein on the virus's outer surface.

However, according to a new study published in the journal Nature Communications, those antibodies do not bind well to newer variants.

According to the University of Illinois at Urbana-Champaign researcher Nicholas Wu, characterizing what types of antibodies the body is most likely to produce to fight a natural infection is an important roadmap for vaccine design.

Hence the researchers used existing articles on Covid-19 patients to find information about the antibody sequences they produced and rather than focusing on antigens that infect human cells, they looked for antibodies that neutralised the virus's spike protein.

The majority of vaccinations are designed to neutralise the spike protein.

They discovered that many antibody sequences converged into two main groups, indicating a consistent human immune response to the virus indicating that the human immune system had a consistent reaction to the pathogen.

Timothy Tan, a graduate student part of the research remarked, "We particularly focused on characterising the antibodies developed in people infected with the original strain of the virus."

The ability of convergent antibodies to bind to various variations was examined by the researchers, and it was discovered that some were no longer bound.

The discovery has ramifications for the capacity of new virus strains to infect people who have previously been infected, as well as for the continued efficacy of vaccines and the creation of prospective vaccine boosters.

"Even though this antibody response is very common with the original strain, it doesn't really interact with variants," Wu said.

"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," Wu added.