Threatening both those who have received vaccinations and those who have already been exposed to the infection, an omicron subvariant is once more displaying immune-dodging powers.
According to a paper published on Wednesday in the New England Journal of Medicine, the subvariant known as BA.4.6 may be responsible for reinfections.
In contrast, BA.5 has been found in about 68% of new cases, according to the Centers for Disease Control and Prevention. As of Friday, BA.4.6 represented slightly more than 12% of new Covid cases in the U.S.
Complete Covid-19 pandemic coverage
Experts from all over the world are monitoring several different strains in addition to these subvariants. Other omicron subvariants that have drawn interest from researchers as well as their concerns include: BF.7, BQ.1, and BQ.1.1. (It turns out that the three represent about 5% of all new cases in the United States.)
The days of referring to Covid by Greek letters like alpha and delta are long gone. It’s been omicron all the way down since the omicron variant first appeared, with omicron subvariants splintering off into their own subvariants.
The study’s lead author, Dr. Dan Barouch, head of the Center for Virology and Vaccine Research at the Beth Israel Deaconess Medical Center in Boston, called it “astonishing” to observe how quickly the virus is evolving. Essentially, “this is viral evolution on steroids.”
Only 35 participants in Barouch’s study had either received the Covid vaccine or had an omicron infection, making it a tiny study. Most had received at least three doses of the Covid vaccination, regardless of prior illness. Blood tests revealed the presence of antibodies designed to counteract BA. 4.6 were around two times less abundant than BA antibodies.
This “indicates that omicron continues to evolve and continues to mutate in a way that becomes more transmissible and more successful at avoiding vaccinations and immune responses,” he said. The findings actually portend the emergence of other variations that may be even more concerning.
Viruses can change at any time, but the changes that give them a competitive advantage over the immune system, vaccinations, or therapies are more likely to persist.
According to Bill Hanage, an associate professor of epidemiology at the Harvard T.H. Chan School of Public Health, “the virus is rapidly diversifying.”
Further complicating matters, different people have varying degrees of immunity, based on the vaccinations they received (or did not receive) and the number of diseases they have experienced.
Hanage remarked, “There is a patchwork of immunity, which allows many hopeful monsters to emerge and transmit.”
Both BA.4 and BA.5 are targeted by the latest Covid booster shots, which were only made accessible last month. However, data on how the new shots perform against BA.4 and BA.5, as well as the multitude of other subvariants, is still lacking.
During a media event on Wednesday, Maria Van Kerkhove, chief of the WHO’s emerging diseases and zoonosis unit, stated that the organization is monitoring more than 300 omicron subvariants globally. They all exhibit greater transmissibility, she claimed.
The omicron subvariants XBB and XAZ have been found in New York City, according to Adriana Heguy, a professor of pathology and the director of the Genome Technology Center at NYU Grossman School of Medicine. The CDC’s variation tracker does not currently include those.
Heguy said, “New York is where everything starts.”
There is no proof that the subvariants are making people sicker even as they spread around the globe.
Van Kerkhove stated, “We don’t observe a difference in severity just yet.”
Heguy reiterated the point. Her team has not yet noticed a rise in hospitalizations linked to Covid.
She remarked, “This is not March 2020, but I think we should proceed with prudence.”
Health on NBC
AA3 and AA4