What are the symptoms? – NBC 5 Dallas-Fort Worth

In recent weeks, a new COVID-19 variant called KP.3 has become dominant in the United States. KP.3 is part of a family of variants nicknamed “FLiRT” and is causing an increasing proportion of cases across the U.S. As KP.3 spreads, some are concerned about a possible summer pandemic.

The FLiRT strains (including KP.3, KP.2 and KP.1.1) now account for more than half of COVID-19 cases nationwide, the latest data showed. Centers for Disease Control and Prevention.

The scientist said, “FLiRT” KP.2, named for the location of the mutation in the spike protein, has been circulating in the United States since early spring, and in April, KP.2 was rapidly JN.1, of Omicron subspecies that is COVID cases surge this winter.

Within a few weeks, the KP.3 variant had overtaken KP.2 as the most prevalent strain in the United States, according to the CDC.

In the two weeks ending June 8, KP.3 is estimated to have accounted for approximately 25% of cases in the United States, up from approximately 9% in early May. The next most common variant after KP.3 is KP.2, a FLiRT variant that also became dominant in May and now accounts for approximately 22% of cases, followed by LB.1, a variant of JN.1, and KP.1.1, another FLiRT variant.

The FLiRT variant accounts for an estimated 55% of cases in the United States.

While hospitalizations are down and COVID-19 cases are relatively low, the latest CDC data shows test positivity rates and emergency room visits are rising slightly — trends that, combined with past summer waves of infections, are stoking fears of a surge in infections this summer.

Scientists have warned that the FLiRT variant may be better able to evade the immune system due to a mutation in the spike protein, and that weakened immunity and low uptake of the latest COVID-19 vaccines are creating populations that are more susceptible to infection.

Will there be a new wave of COVID-19? What are the symptoms of the FLiRT variant? Is the vaccine still effective? We spoke to experts to find out more.

What is KP.3?

KP.3 is one of the FLiRT variants, along with KP.2 and KP.1.1, which are derived from JN.1.11.1, a direct descendant of JN.1, that were initially detected in wastewater samples across the country.

KP.3 and the other new variants have additional mutations that set them apart from JN.1, which appear to give them an advantage over earlier variants, Dr. Albert Ko, an infectious disease physician and professor of public health, epidemiology and medicine at the Yale School of Public Health, told TODAY.com.

The “FLiRT” nickname is based on the variant's terminology. Infectious Diseases Society of America.

Like other COVID-19 strains (JN.1) that have become dominant in the United States over the past year, HV.1, EG.5 aka Ellisand XBB.1.16 or Arcturus — FLiRT variants Omicron Family.

The emergence of KP.3 and other FLiRT variants is “a pattern we've always seen,” Dr. Andrew Pecos, a virologist at Johns Hopkins University, told TODAY.com. The SARS-CoV-2 virus mutates to produce new, more infectious variants that become the dominant strain. “The time it takes for mutations to occur is three to six months, which is much faster than other viruses, like influenza,” Dr. Pecos said.

Is KP.3 more contagious?

“It's still early days, but our initial impression is that this variant is significantly more transmissible,” Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center, told TODAY.com.

While the proportion of cases caused by KP.3 is increasing, the proportion of cases caused by other variants is decreasing, suggesting that the FLiRT variant has characteristics that give it an advantage, experts note.

According to the CDC, more than 97% of people in the United States have natural or vaccine-induced antibodies against the SARS-CoV-2 virus, but this immune protection wanes over time.

Low vaccination rates and waning immunity could create a vulnerable population, allowing the FLiRT variant to spread. Experts say only time and more data will reveal the answer.

Schaffner said laboratory studies suggest the FLiRT variant is so mutated that current vaccines and immunity from previous infection may only provide partial protection. “We'll have to see how true that is, but it does appear to be becoming a more prominent variant over time,” he added.

“It's still really early, but I don't think there's any need to sound any alarm bells right now,” Ko said.

COVID Situation in the United States

Experts say it remains to be seen whether the KP.3 and FLiRT variants will cause a summer wave or surge, but what's clear is that COVID-19 is still spreading and showing no signs of respite.

“We see these infections at varying levels throughout the year. … We probably aren't at the point yet where we're going to be completely COVID-free at any time of the year,” Pecos said.

The test positivity rate, an early indicator of the number of infected people, was 5.4% as of June 8, up 0.8% from the previous week but down significantly from a peak of about 12% in mid-January. According to the CDC:(The CDC no longer tracks the total number of cases in the US)

“Hospitalization numbers are not that high and are certainly much lower than they were in the winter, so we can say they're at a low point at the moment, which is reassuring,” Coe said.

Wastewater Data Data released by the CDC says levels of COVID-19 viral activity are currently “low,” but were considered high or very high for much of January and February.

“Infections seem to be quite low at the moment, but that's understandable because typically peak infections occur in the winter when people are indoors and have more contact,” Koh said.

COVID-19 caused a summer wave Experts say past spikes in cases have often been smaller than winter surges. “I don't expect to see such a big surge in cases,” Pecos said.

Scientists are still trying to understand the seasonality of COVID-19, but one thing is clear: “This virus is now integrated into our population and our way of life,” Schaffner said.

Ko added: “We do not expect a surge in cases in the summer, but again, we must remain vigilant and follow the data. … SARS-CoV-2 has taught us many new things, so we must always remain humble.”

What are the symptoms of KP.3?

It is still too early to tell if symptoms of KP.3, KP.2 and other FLiRT variants differ from previous strains.

“The FLiRT variant probably won't cause very distinctive symptoms. At this point, it looks like it will cause symptoms similar to other subvariants,” Schaffner said.

Symptoms of FLiRT mutants are similar to those caused by JN.1 and include:

• sore throat
• cough
• Malaise
• congestion
• snot
• headache
• muscle pain
• Fever or chills
• New loss of taste or smell
• Shortness of breath or difficulty breathing
• Nausea or vomiting
• diarrhea

According to the CDC, the type and severity of symptoms a person experiences usually depends more on a person's underlying health and immune system than on the variant causing the infection.

Like JN.1 and other Omicron variants, the FLiRT variant appears to cause milder infections, Schaffer said.

Does the vaccine prevent KP.3?

Early laboratory studies suggest the vaccine continues to provide protection against the FLiRT variant, “so the protection drops off a little bit, but it's never zero,” Schaffner said.

As the virus mutates, it is becoming increasingly different from the targeted Omicron strain. Latest Booster It's expected to be released in the fall of 2023. “We expect that to happen, and we think that an updated vaccine will be available to everyone in the fall,” Schaffner said.

The advisor is U.S. Food and Drug Administration The WHO met on Tuesday, June 5, to decide which strains will be included in the updated COVID-19 vaccine in 2024-2025. The committee unanimously resolved to recommend a monovalent vaccine targeting the JN.1 variant this fall, the agency announced in a press release.