December 16, 2022 – It’s a story that might be more appropriate for Halloween than the festive holiday, given its unsettling implications. Four omicron subvariants of the virus that causes COVID-19 will be the most common strains transmitted from person to person this winter, new evidence predicts.
Not too bad so far, until you consider what else the researchers found.
Subvariants BQ.1, BQ1.1, XBB, and XBB.1 are the most resistant to neutralizing antibodies, report researcher Qian Wang, PhD, and colleagues. This means that you have no or “significantly reduced” protection against infection with these four strains, even if you have already had COVID-19 or have been vaccinated and boosted multiple times, including with a bivalent vaccine.
Furthermore, all available monoclonal antibody treatments against these subvariants are largely or completely ineffective.
What does this mean for our immediate future? The results are definitely “worrying,” says Eric Topol, MD, founder and director of the Scripps Translational Research Institute in La Jolla, Calif., and editor-in-chief of Medscape, WebMD’s sister website for healthcare professionals.
But evidence from other countries, particularly Singapore and France, shows that at least two of these variants have not turned out to be as harmful as expected, likely because of the high numbers of people vaccinated or those who survived previous infections, Topol says.
Still, there’s little to celebrate in the new findings, other than that COVID-19 vaccinations and previous infections can still reduce the risk of serious outcomes like hospitalization and death, the researchers say.
The “Alarming Antibody Evasion Properties of Rising SARS-CoV-2 BQ and XBB Subvariants” Study was published online this week in the Journal cell.
It comes at a time when BQ.1 and BQ.1.1 account for about 70% of circulating variants, show CDC data. Additionally, hospital admissions are up 18% in the past 2 weeks and COVID-19 deaths are up 50% nationwide. The New York Times reports.
An “immunity wall” has been erected in many places around the world, says Topol. That may not be the case in the United States.
“The problem in the US that makes it harder to predict is that we have a very low rate of new booster shots over the past 6 months, especially among seniors,” says Topol. For example, only 36% of Americans 65 and olderthe group at highest risk, have received an updated bivalent booster dose.
An evolving virus
The sub-variants successfully replace BA.5, which last year asserted itself as one of the most widespread Omicron variants. The latest CDC data shows that BA.5 now accounts for only about 10% of the circulating virus. The researchers write: “This rapid displacement of virus strains “raises the specter of another wave of infections in the coming months”.
The story sounds familiar to researchers. “The rapid rise of these subvariants and their extensive spectrum of spike mutations are reminiscent of the appearance of the first Omicron variant last year and raise concerns that they may further compromise the efficacy of current COVID-19 vaccines and monoclonal antibody therapeutics.” , say they write. “We now report results indicating that such concerns are unfortunately justified, particularly for the XBB and XBB.1 subvariants.”
The subvariant BQ.1 was 6-fold more resistant to antibodies than BA.5, its parent strain, and XBB.1 was 63-fold more resistant compared to its predecessor BA.2.
This shift in vaccines’ ability to stop the subvariants “is of particular concern,” the researchers write.
Also wipe out treatments
Wang and colleagues also tested how well a panel of 23 monoclonal antibody drugs might work against the four subvariants. The therapies all worked well against the original Omicron variant and included some that were approved for use by the FDA’s Emergency Use Authorization (EUA) program at the time of the study.
They found that 19 of these 23 monoclonal antibodies against XBB and XBB.1, for example, lost potency “severely or completely”.
This is not the first time monoclonal antibody therapies have gone from being effective to ineffective. Earlier variants have become known that no longer responded to treatment with bamlanivimab, casirivimab, cilgavimab, etesevimab, imdevimab, sotrovimab and tixagevimab. Bebtelovimab now joins this list and is no longer available from Lilly under EUA due to this lack of effectiveness.
The lack of effective monoclonal antibody treatment “poses a serious concern for millions of immunocompromised individuals who do not respond robustly to COVID-19 vaccines,” the researchers write, adding, “The urgent need to develop active monoclonal antibodies for clinical use.” Developing commitment is obvious. ”
Looking ahead, the challenge remains to develop vaccines and treatments that offer broad protection as the coronavirus evolves.
In a chilling ending to a chilling story, the researchers write, “We’ve been hunting SARS-CoV-2 variants together for over 2 years, and yet the virus continues to evolve and elude.”