New data offer glimpse at potential impact of emerging COVID variants

Data from two preprint studies offer some inkling of what challenges the latest COVID-19 variant brings. In the last two weeks BF.7 has doubled its incidence in the United States from 0.8% to 1.7%. The largest growth has been in the Northeast, where the incidence is now over 3%, according to data from the Centers for Disease Control and Prevention (CDC).

BF.7 (also known as BA.2.75.2) began as a subvariant of B.5, which is a subvariant of omicron B.1.1.529. So, it started as a sub-subvariant but has grown so rapidly that the CDC placed it in its own category. Two preprint studies, one from Sweden and the other from China, conclude that BF.7 can escape the antibodies from vaccines or previous infection better than the many other subvariants of omicron (BA.2, BA.3, BA.4, as well as BA.5). The studies were first reported in The New York Times.

Swedish researchers measured the effectiveness of Evusheld against emerging omicron subvariants in blood donor samples. Evusheld (tixagevimab and cilgavimab) is meant to prevent infection by SARS-CoV-2 in people 12 and older who “are not infected and have not had a recent exposure to an individual known to be infected with SARS-CoV-2,” according to the U.S. Department of Health and Human Services. They conclude that “BA.2.75.2 [is] the most neutralization resistant variant evaluated to date. These data raise concerns that BA.2.75.2 may effectively evade humoral immunity in the population.”

Chinese researchers note that the “evolution of Omicron has led to numerous subvariants that exhibit growth advantage over BA.5. Such rapid and simultaneous emergence of variants with enormous advantages is unprecedented…. The driving force and destination of such convergent evolution and its impact on humoral immunity established by vaccination and infection remain unclear.”

They add that their findings “demonstrate that these convergent mutations can cause striking evasion of convalescent plasma, including those from BA.5 breakthrough infection, and existing antibody drugs, including Evusheld and Bebtelovimab. BA.2.75.2 is the most evasive strain tested, and only BQ.1.1 could compare.”

Bebtelovimab is a monoclonal antibody that works against SARS-CoV-2’s spike protein. The U.S. Food and Drug Administration approved the drug under emergency use authorization in February as a treatment for mild-to-moderate COVID-19 in individuals older than 12.

BQ.1.1 is yet another new variant that’s recently emerged, though it has not yet been studied in any depth by the scientific community. It’s too new, a point made on Twitter by Cornelius Roemer, a physicist major at Cambridge University, who wrote that BQ.1.1 is “showing quite some growth, especially in England where the first sample was submitted 9 days ago and now there are already 28 sequences. I hope there is some sort of biased sampling going on. Otherwise, this doesn’t look good.”

Many experts, including medical officials with the CDC, point out that we have the medical weapons to battle COVID-19 that we didn’t have when the virus first surfaced—before there were even vaccines. They concur with the assessment of Tedros Adhanom Ghebreyesus, the head of the World Health Organization, who last week said that the end of the pandemic is in sight. And even the emergence of the new sub-subvariants need to be considered in context.

The New York Times reports that “for now, BA.2.75.2 is extremely rare, making up just .05 percent of the coronaviruses that have been sequenced worldwide in the past three months. But that was once true of other omicron subvariants that later came to dominate the world. If BA.2.75.2 becomes widespread this winter, it may blunt the effectiveness of the newly authorized boosters from Moderna and Pfizer.”

Still, the newspaper notes that what makes the many COVID-19 variants “even more puzzling was that they arose independently. Beta did not descend from Alpha. Instead, it arose with its own set of new mutations from a different branch of the SARS-CoV-2 tree…. Instead of jumping from one host to another, they created chronic infections in people with weakened immune systems.”

Early data must also be viewed with a healthy dose of skepticism, although those are the data that are more timely when fighting such a fast-evolving virus.

When COVID-19 first surfaced and experts scrambled to understand just what they fought and how best to fight it, the peer-reviewed process couldn’t keep up. By the time peer-reviewed studies about the alpha (B.1.1.7) had been published, the beta (B.1.351) variant had arrived. Then came gamma (P.1), delta (B.1.617.2), omicron (B.1.1.529) and all the subvariants of omicron, arriving faster than the time it usually takes for an academic study to be submitted, peer-reviewed, accepted, and published.

Not that some journals didn’t try to speed things up. A study in April 2021 in the Journal of Anesthesiology Clinical Pharmacology compared the length of time from acceptance to publication in 16 anesthesiology journals from January to September 2020 to articles published in 2019.

The median peer review time in 2019 was 116 days; that dropped to 79 days in 2020, but for COVID-19 articles, the median dropped to 35 days. “A 55.6% decrease was noted in peer review time of COVID-19 articles compared to non-COVID-19 articles in 2020,” the study stated.