Most people have the ability to produce neutralizing antibodies against the novel coronavirus in severe cases of COVID-19, a new study reveals supporting the use of combination antibody therapy to prevent and treat the disease.
In the study, the researchers point out that neutralizing antibodies that specifically target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, which the virus relies on to enter human cells, are essential for controlling it.
During the study, the researcher team detected the presence of RBD-specific neutralizing antibodies in convalescent patients, those who have recovered from COVID-19. Some of the recovered patients have robust and long-lasting immunity, while others show a decrement in the amount of neutralizing antibodies over time.
The study, published in the journal PLOS Pathogens, used molecular and bioinformatics techniques to compare B-cell responses in eight patients with severe COVID-19 and 10 individuals with mild symptoms for one and half months after infection.
B-cells of the immune system is responsible for mediating the production of antigen-specific immunoglobulin (Ig) directed against invasive pathogens. The research also found that only a few patients displayed higher concentrations of RBD-specific antibodies and increased B-cell expansion. Out of 22 antibodies cloned from two of the patients, six exhibited potent neutralization against SARS-CoV-2.
“Bioinformatics analysis suggests that most people would be capable of readily producing neutralizing antibodies against SARS-CoV-2 in severe cases of COVID-19,” they noted.
Moreover, the study shows that combinations of different types of neutralizing antibodies completely blocked the live virus from spreading. According to the researchers, these antibody cocktails can be further tested in clinical settings as a useful means to prevent and treat COVID-19.
“Even with a vaccine at our doorstep, arming clinicians with specific anti-SARS-CoV-2 therapeutics is extremely important. Combinations of neutralizing antibodies represent a promising approach towards effective and safe treatment of severe COVID-19 cases, especially in the elderly population or chronically ill people, who will not be able to so easily produce these antibodies upon infection or vaccination,” the researchers added.