Over the past few months, most COVID-19 cases in the U.S. have been Omicron subvariants BA.4 and BA.5. But now, a group of new COVID-19 subvariants is becoming more common, and one of them is getting a lot of attention. It is called XBB or Gryphon, and there is a chance that it could take over everything else.
William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine, says that XBB is getting a lot of attention because it spreads quickly and seems to be able to get around the immunity that people have built up from having COVID-19 before or getting the vaccine. Still, Dr. Schaffner says, “It’s early, and we have a lot to learn.”
Here is what we know so far about XBB and why doctors are paying close attention to it.
What does XBB COVID stand for?
Thomas Russo, M.D., professor and chief of infectious disease at the University at Buffalo in New York, says that XBB is one of the “new class” of Omicron variants that are spreading quickly right now. He says that’s true for BQ.1.1, BQ.1, BQ.1.3, BA.2.3.20, and XBB.
Amesh A. Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security, says that XBB is a mix of two strains of the BA.2 form of Omicron. He also says that it is “spreading quickly in Singapore.”
The first time the variant was found was in India in August 2022. Since then, it has been found in more than 17 countries, including Australia, Bangladesh, Denmark, India, Japan, and the United States.
Researchers in China think that XBB is the most likely to be able to get around the antibody protections of these new COVID variants. This is based on a study that has not yet been published. In that study, it was said that the new strains of Omicron, and XBB in particular, “are the most antibody-evasive strain tested, far surpassing BA.5 and getting close to SARS-CoV-1 level.” If you don’t know, SARS-CoV-1 is the strain of coronavirus that causes SARS, a virus that affects the lungs that can make you very sick.
It is thought that the vaccine and having had COVID-19 in the past won’t protect against XBB as well as they did against other strains of COVID-19. The study says that antibody drugs like Evusheld and bebtelovimab may not work very well against XBB either.
“These variants are getting better at getting around protection,” says Dr. Russo. Dr. Russo says that the bivalent booster is “likely to protect against severe disease” with XBB, but it won’t be “perfect” at stopping infections.
But don’t get too worried. “It’s important to know that vaccine protection is not all or nothing when it comes to avoiding vaccines,” says Dr. Adalja. “Even with immune-evasive variants, vaccines still protect against the most important thing, which is severe disease.”
XBB variant symptoms
So far, the symptoms of XBB seem to be the same as the general symptoms of COVID-19. According to the Centers for Disease Control and Prevention (CDC), these can include:
- Fever or chills
- Cough Shortness of breath or trouble breathing
- Fatigue
- Muscle or body aches
- Headache
- New loss of taste or smell
Sore throat
- Congestion or runny nose
- Nausea or vomiting
- Diarrhea
How easy is the XBB subvariant to spread?
People think that XBB is very contagious, just like other strains of Omicron. The Ministry of Health in Singapore says that 54% of COVID-19 cases in the country now involve the variant, which is up from 22% the week before.
The Ministry of Health in Singapore says that XBB is “at least as contagious as currently circulating variants,” but that there is no evidence that XBB makes illness worse.
When will the subvariant XBB reach its peak?
Right now, there is a lot we don’t know about XBB. Even though it has been found in the U.S., CDC data shows that BA.5 and BA.4.6 are still the most common types.
Dr. Adalja says that other variants are also spreading at the same time, and it’s not clear which will replace BA.4.6 and BA.5 in the U.S., if they do. He says, “It’s likely to spread a little bit in the U.S., but it’s not clear if it or a related variant like BQ.1.1 will take over.”
Dr. Schaffner says that there is “some worry” about the rise of XBB and other variants. “It’s important to keep an eye on the next few weeks,” he says.
As of the time of press, this article is correct. But as the COVID-19 pandemic changes quickly and scientists learn more about the new coronavirus, some of the information may have changed since the last time it was updated. We try to keep all of our stories up-to-date, but if you really want to know what’s going on, please check out the CDC, WHO, and your local public health department’s websites. Talk to your doctor for professional advice about your health.
