A staff member draws up a syringe with the Comirnaty vaccine from Biontech and Pfizer adapted to the Omicron-BA.1 variant on the Mainz vaccination center.
Sebastian Christoph Gollnow | dpa | Picture Alliance | Getty Images
Covid shots designed to guard against the omicron variant trigger a weaker immune response against the rapidly emerging BQ.1.1 subvariant than the previously dominant strain, in response to a latest lab study.
Scientists on the University of Texas Medical Branch, in a study published online Tuesday in Nature Medicine, found that the booster shots performed well against the BA.5 subvariant they were designed to focus on.
However the boosters didn’t trigger a strong response when faced with BQ.1.1, the scientists found. Antibodies were about 4 times lower against BQ.1.1 in comparison with BA.5. These neutralizing antibodies prevent the virus that causes Covid-19 from invading human cells.
Individuals with a previous history of infection who received an omicron booster, nevertheless, had a stronger response to BQ.1.1. Antibodies that neutralize BQ.1.1 were nearly 4 times higher on this group in comparison with individuals with no history of infection who faced the subvariant, the scientists found.
About 42% of adults within the U.S. have a previous history of infection, in response to study published by the Centers for Disease Control and Prevention last week. The outcomes were based on adult blood samples collected from from August 2021 through May 2022.
Omicron BQ.1.1 subvariant appears on course to turn out to be the dominant variant within the U.S. It currently makes up about 32% of infections within the U.S., in response to CDC surveillance data. Omicron BA.5, however, now represents about 14% of latest infections.
The boosters performed the weakest against the XBB.1 subvariant, the scientists found. Antibodies were greater than eight times lower against XBB.1 than omicron BA.5. Nevertheless, individuals with a previous history of infection who receive the booster had thrice as many antibodies against XBB.1 than individuals with no Covid history, in response to the study.
Dr. Anthony Fauci, White House chief medical advisor, said last month protection provided by the boosters drops somewhat against BQ.1.1, but diminishes multifold against XBB.
“So, you would 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 individuals with no history of infection who received the omicron booster; 23 samples from individuals who received the booster who did have a history of infection; and 25 individuals who received a fourth dose of the unique vaccine.
The samples were collected 14 to 32 days after the omicron booster and 23 to 94 days after the fourth dose of the unique vaccine.
