A person receives a test for the coronavirus disease (COVID-19) as the Omicron variant of the coronavirus continues to spread in Manhattan, New York City, USA, on December 22, 2021.
Andrew Kelly | Reuters
Omicron BQ subvariants of the coronavirus have become dominant in the US as people gather and travel for the Thanksgiving holiday, putting people with compromised immune systems at increased risk.
BQ.1 and BQ.1.1 cause 57% of new infections in the US, according to data released Friday by the Centers for Disease Control and Prevention. The omicron BA.5 subvariant, once dominant, now accounts for only a fifth of new Covid cases.
BQ subvariants are more evasive and likely resistant to key antibody drugs such as Evusheld and bebtelovimab used by people with compromised immune systems, according to the National Institutes of Health. These include organ transplant patients and cancer chemotherapy patients.
There are currently no substitutes for these drugs. In a speech in October, President Joe Biden told people with compromised immune systems to consult their doctors and take special precautions this winter.
“New variants may render some existing protections ineffective for the immunocompromised. Unfortunately, that means you may be at particular risk this winter,” Biden said.
The XBB subvariant also now circulates at a low level and causes about 3% of new infections. Dr. Anthony Fauci said at a White House briefing earlier this week that XBB is even more immune than sub-variants of BQ.
Fauci said the new boosters that have been designed against omicron BA.5 are probably not as effective against infection and mild disease caused by XBB. But according to him, the injections should protect against severe disease. Singapore has seen a sharp increase in cases from XBB, but there has not been a large increase in hospitalizations, he added.
Moderna and Pfizer said last week that their boosters elicit an immune response against BQ.1.1, a descendant of the BA.5 subvariant.
Fauci said at a press conference this week that public health officials believe there is enough immunity from vaccination, boosting and infection to prevent a repeat of the unprecedented surge in Covid that occurred last winter when the micron first arrived.