Wiping out treatments too
Dr. Wang and colleagues also tested how well a panel of 23 different monoclonal antibody drugs might work against the four subvariants. The therapies all worked well against the original Omicron variant and included some approved for use through the Food and Drug Administration emergency use authorization (EUA) program at the time of the study.
They found that 19 of these 23 monoclonal antibodies lost effectiveness “greatly or completely” against XBB and XBB.1, for example.
This is not the first time that monoclonal antibody therapies have gone from effective to ineffective. Previous variants have come out that no longer responded to treatment with bamlanivimab, etesevimab, imdevimab, casirivimab, tixagevimab, cilgavimab, and sotrovimab. Bebtelovimab now joins this list and is no longer available from Eli Lilly under EUA because of this lack of effectiveness.
The lack of an effective monoclonal antibody treatment “poses a serious problem for millions of immunocompromised individuals who do not respond robustly to COVID-19 vaccines,” the researchers wrote, adding that “the urgent need to develop active monoclonal antibodies for clinical use is obvious.”
A limitation of the study is that the work is done in blood samples. The effectiveness of COVID-19 vaccination against the BQ and XBB subvariants should be evaluated in people in clinical studies, the authors noted.
Also, the current study looked at how well antibodies could neutralize the viral strains, but future research, they added, should look at how well “cellular immunity” or other aspects of the immune system might protect people.
Going forward, the challenge remains to develop vaccines and treatments that offer broad protection as the coronavirus continues to evolve.
In an alarming ending, the researchers wrote: “We have collectively chased after SARS-CoV-2 variants for over 2 years, and yet, the virus continues to evolve and evade.”
A version of this article first appeared on Medscape.com.