- New COVID-19 variant fuels infections in US
- KP.3.1.1 is currently the second most common variant in the country.
- Experts say this variant may be more contagious than previous variants.
The United States continues to ride the COVID summer wave. Emergency room visits, hospitalizations, and deaths from COVID-19 are up, putting the virus back in the spotlight. But a new variant has emerged quickly that is fueling cases. It’s called KP.3.1.1.
According to data from the Centers for Disease Control and Prevention (CDC), it is currently the second most prevalent variant of COVID-19 in the United States. This variant appeared as a small blip on the radar in early June and quickly gained momentum, surpassing variants like LB.1 that had previously garnered a lot of attention.
Meet the experts:Amesh A. Adalja, MD, is an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security, William Schaffner, MD, an infectious disease expert and professor at Vanderbilt University School of Medicine, John Sellick, DO, an infectious disease expert and professor of medicine at the University at Buffalo SUNY
But what is KP.3.1.1 and is it more contagious than other variants? Experts explain.
What is KP.3.1.1?
KP.3.1.1 is a new variant of COVID-19 that is currently causing nearly 18% of cases of the virus in the United States. KP.3.1.1 is a sublineage of KP.3, which is the most common variant in the United States right now. “It’s another subvariant of the Omicron family,” says Dr. William Schaffner, an infectious disease specialist and professor at Vanderbilt University School of Medicine.
KP.3.1.1 is also an offshoot of the FLiRT variants that made headlines in late spring, says Dr. Amesh A. Adalja, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security.
KP.3.1.1 “has an additional mutation in its spike protein,” Dr. Adalja says. (The spike protein is what SARS-CoV-2 uses to latch onto your cells and infect you.)
There isn’t a lot of data on KP.3.1.1, but there is some. Researchers in Japan analyzed KP.3.1.1 and found that it was a subvariant of the older JN.1, which was the dominant virus in the United States in the spring. It is also related to LB.1.
These variants emerge quickly because they are able to mutate and adapt quickly, Dr. Schaffner explains.
Symptoms KP.3.1.1
There isn’t much information about the symptoms of KP.3.1.1 at this time, given how new the variant is. However, Dr. Adalja says the symptoms of this strain are similar to other SARS-CoV-2 mutations. “The symptoms of all versions of the virus are similar,” he says.
In case you need a refresher, here are the most common symptoms of COVID-19, according to the CDC:
- Fever or chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue
- Muscle or body pain
- Headache
- New loss of taste or smell
- Sore throat
- Nasal congestion or runny nose
- Nausea or vomiting
- Diarrhea (which anecdotally may be an early symptom of this variant)
“At this time, there is no evidence of a difference in severity with KP.3.1.1,” says John Sellick, DO, an infectious disease expert and professor of medicine at the University at Buffalo SUNY.
East KP.3.1.1 more contagious than previous variants?
Yes, preliminary research has found that the KP.3.1.1 variant is more contagious than previous variants. In fact, this analysis found that the variant has “significantly higher infectivity” compared to the KP.3 variant, which is already considered a highly contagious variant.
“What we know about this variant is still quite limited, but it does appear to be quite contagious even though it does not appear to be more severe,” says Dr. Schaffner.
Given how quickly this variant has spread in the country and its spike protein mutation, Dr. Adalja believes it is likely to be more contagious than KP.3.
Will the COVID-19 vaccine be effective against KP.3.1.1?
The current vaccine, which targets the XBB.1.5 strain of COVID-19, appears to help prevent severe disease in people at high risk of severe COVID-19 infection, Dr. Adalja says. However, “it hasn’t been very effective or durable in blocking infection with any of the newer variants,” he says.
Recent research on KP.3.1.1 has also found that it has “enhanced immune evasion” compared to other JN.1 subvariants. This means that the vaccine is even less likely to be effective in preventing infection with KP.3.1.1. (Although, again, it should help protect against severe disease.)
The next COVID-19 vaccine coming to market in the fall will target the KP.2 strain (Moderna and Pfizer vaccines) and the JN.1 strain (Novavax vaccine). Since the KP.3.1.1 strain is a descendant of the JN.1 strain and is also related to the KP.2 strain, another sublineage of the JN.1 strain, the new vaccine should be effective against it, says Dr. Schaffner.
However, more data is needed. “This is a question that we will have to study in the laboratory,” says Dr. Schaffner. “So far, the vaccine planned for the fall has covered all the variants up to this one.”
How to reduce your risk of contracting KP.3.1.1
Prevention for the KP.3.1.1 variant is the same as for other variants. That is, do your best to avoid people who are obviously sick and wear a mask indoors (like a KN95 or N95) if you are considered at high risk for serious complications from the virus.
“This is an endemic respiratory virus that is difficult to completely avoid if you interact in person with other humans,” says Dr. Adalja. It’s also important to be up-to-date on your COVID-19 vaccinations, especially if you’re considered high risk, adds Dr. Schaffner.
If you are severely immunocompromised, Dr. Adalja recommends talking to your doctor about the monoclonal antibody Pemgarda, which can help reduce your risk of getting sick.
But Dr. Adalja stresses that people shouldn’t panic about this new variant. “Variants will always emerge, in perpetuity, because that’s how evolution works,” he says. “There will always be a variant that comes along and others that disappear. The virus is relatively new to humans and is under a lot of pressure from population immunity. So it’s evolving to stay viable, as you would expect.”
Dr. Sellick agrees. “We’re going to continue to see new variants emerge, just like we continue to see new strains of influenza emerge pretty regularly,” he says.
Korin Miller is a freelance writer specializing in general wellness, sexual health and relationships, and lifestyle trends. Her work has appeared in Men’s Health, Women’s Health, Self, Glamour, and more. She has a master’s degree from American University, lives near the beach, and hopes to one day own a teacup pig and a taco truck.