No virus variants can evade all antibody types

(Reuters) – The human immune system makes many antibodies in response to COVID-19 infection or vaccination, and no single variant of the new coronavirus can yet escape all of them, according to a study posted on Thursday on bioRxiv ahead of peer review. Researchers looked at how mutations in coronavirus variants affect antibodies’ ability to target a key region on the virus spike called the receptor binding domain (RBD), which has been mutating rapidly. In particular, the researchers studied three sets of antibodies that were classified by the structural features that affect their binding to the virus. Despite the diversity of antibodies, just one class dominates the antibody response that targets the RBD, they found. They also looked to see how many different classes of antibodies can be evaded by new coronavirus variants. “Several lineages have mutations that reduce binding by two of the antibody classes, but so far no lineages have mutations that escape all three classes,” said coauthor Jesse Bloom of the Fred Hutchinson Cancer Research Center in Seattle. “We suggest this is an important thing to keep an eye on as the virus continues to evolve.”