The BQ and XBB subvariants of the COVID-19 virus Omicron are spreading rapidly and have altered antibody evasion properties that make them more difficult to neutralize with current vaccines and monoclonal antibodies, according to a new publication in the peer-reviewed scientific journal Cell.
According to the study, coronavirus subvariants called BQ and XBB have changes in their spike proteins that may make them harder to fight with current vaccines and treatments. “The BQ and XBB subvariants of SARS-CoV-2 Omicron are now rapidly expanding, possibly due to altered antibody evasion properties deriving from their additional spike mutations,” the study says.
The paper shows that these subvariants are not as easily neutralized by the immune system, including in people who have received COVID-19 vaccines or have previously been infected with the virus. “Here, we report that neutralization of BQ.1, BQ.1.1, XBB, and XBB.1 by sera from vaccinees and infected persons was markedly impaired, including sera from individuals boosted with a WA1/BA.5 bivalent mRNA vaccine,” write the authors from Columbia University and the University of Michigan.
The study authors conclude that their findings “indicate that BQ and XBB subvariants present serious threats to current COVID-19 vaccines, render inactive all authorized antibodies, and may have gained dominance in the population because of their advantage in evading antibodies.”
The BQ.1, BQ.1.1, XBB and XBB.1 omicron subvariants are the most immune evasive variants of Covid-19 to date, according to scientists affiliated with Columbia University and the University of Michigan. These variants, taken together, are currently causing 72% of new infections in the U.S., according to data from the Centers for Disease Control and Prevention. The scientists, in a study published online Tuesday in the peer-reviewed journal Cell, found that these subvariants are “barely susceptible to neutralization” by the vaccines, including the new omicron boosters. The immune response of people who were vaccinated and had breakthrough infections with prior omicron variants also was weaker against the subvariants.