According to a new lab study, covid shots designed to protect against the omicron variant produce a weaker immune response against the rapidly emerging BQ.1.1 subvariant than the previously dominant strain.
In a study published online Tuesday in Nature Medicine, researchers at the University of Texas Medical Branch discovered that the booster shots performed well against the BA.5 subvariant they were designed to target.
However, when confronted with BQ.1.1, the scientists discovered that the boosters did not elicit a robust response. Antibodies against BQ.1.1 were approximately four times lower than against BA.5. The virus that causes Covid-19 is prevented from invading human cells by these neutralising antibodies.
People who had previously been infected and received an omicron booster, on the other hand, had a stronger response to BQ.1.1. Antibodies that neutralise BQ.1.1 were nearly four times higher in this group than in individuals with no history of infection who were exposed to the subvariant, the researchers discovered.
The scientists discovered that the boosters performed the worst against the XBB.1 subvariant. Antibodies against XBB.1 were more than eight times lower than antibodies against omicron BA.5. According to the study, people with a prior history of infection who received the booster had three times as many antibodies against XBB.1 as people with no Covid history.
Dr. Anthony Fauci, White House chief medical advisor, stated last month that booster protection diminishes slightly against BQ.1.1 but multiplies against XBB.
So, you could expect some protection, but not the optimal protection,” Fauci told reporters at a White House press briefing before the Thanksgiving holiday.
The Texas study examined blood samples of 29 people with no history of infection who received the omicron booster; 23 samples from people who received the booster who did have a history of infection; and 25 people who received a fourth dose of the original vaccine.
The samples were collected 14 to 32 days after the omicron booster and 23 to 94 days after the fourth dose of the original vaccine.