The KP.3.1.1 variant remains the most prevalent strain of COVID-19 in the United States, responsible for nearly 60% of confirmed cases, according to the latest data from the Centers for Disease Control and Prevention (CDC). However, the XEC variant is gaining traction, positioned closely behind.

According to CDC spokesperson Rosa Norman, “CDC is keeping an eye on the XEC variant. XEC is the proposed name for a recombinant hybrid formed by two closely related Omicron lineages, KS.1.1 and KP.3.3.”

This variant was first identified in Berlin in late June and has been linked to rising case numbers in Germany, France, Denmark, and the Netherlands, as reported by Australian data integration expert Mike Honey.

The CDC’s Nowcast data tracking tool indicates that the KP.3.1.1 variant constituted 57.2% of positive COVID-19 tests, while XEC accounted for 10.7% during the two-week period from September 29 to October 12.

KP.3.1.1 became the leading variant between July 21 and August 3.

Recent statistics indicate that the prevalence of both variants has increased since September 15-28, with KP.3.1.1 climbing by 4.6% and XEC by 5.4%. Previously, KP.3.1.1 made up 52.6% of cases and XEC was at 5.3% during that timeframe.

Here’s what you need to understand about the XEC variant and the latest findings from the CDC.

What are the most prevalent variants in the United States?

The CDC’s Nowcast data tracker reveals the current dominant strains among the top 10 variants.

Current Wastewater Viral Activity Levels for COVID-19

Note: Wastewater data is typically updated weekly, and results reflect the week prior. These results may take up to five days to a week to be made available online. Therefore, data from October 5 is the most current.

The following map illustrates the wastewater viral activity levels reported by states and territories, published on October 10.

The map indicates the viral activity levels by state and territory as follows:

• Very High: Two states
• High: 14 states
• Moderate: 11 states
• Low: 15 states
• Minimal: seven states; one territory
• No Data: one state; one territory

Weekly Changes in COVID-19 Test Positivity Rates

The CDC’s data indicates an overall decrease in positivity rates, with the four states in Region 10 experiencing the largest decline (-2.7%) in positive COVID-19 cases from September 29, 2024, to October 5, 2024.

This information was published on October 11.

Note: The CDC categorizes positivity rates by regions as defined by the U.S. Department of Health and Human Services.

Below is a summary of changes in COVID-19 positivity across states by region over the past week:

• Region 1 (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont): -2%
• Region 2 (New Jersey, New York, Puerto Rico, Virgin Islands): -1.9%
• Region 3 (Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, West Virginia): -1.3%
• Region 4 (Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee): -0.6%
• Region 5 (Illinois, Indiana, Michigan, Minnesota, Ohio, Wisconsin): -2%
• Region 6 (Arkansas, Louisiana, New Mexico, Oklahoma, Texas): -0.8%
• Region 7 (Iowa, Kansas, Missouri, Nebraska): -1.7%
• Region 8 (Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming): -1.2%
• Region 9 (Arizona, California, Hawaii, Nevada, American Samoa, Northern Mariana Islands, Federated States of Micronesia, Guam, Marshall Islands, Republic of Palau): -1.3%
• Region 10 (Alaska, Idaho, Oregon, Washington): -2.7%

The CDC reports a positivity rate of 7.7% from September 29 to October 5, reflecting a decrease of -1.8% from the previous week.

COVID-19 Symptoms

The current variants circling in the U.S. do not present unique symptoms, according to the CDC.

The agency lists basic COVID-19 symptoms on its website, which typically manifest between two and 14 days post-exposure and may range from mild to severe.

Some common COVID-19 symptoms include:

• • • Fever or chills
    • Cough
    • Shortness of breath or trouble breathing
    • Tiredness
    • Muscle or body pain
    • Headaches
    • Lack of taste or smell
    • Sore throat
    • Stuffed or runny nose
    • Nausea
    • Nausea or vomiting
    • Diarrhea
  • The CDC recommends that you contact a healthcare provider if you experience any of the following symptoms:
    • Difficulty breathing
    • Ongoing pain or pressure in the chest
    • Sudden confusion
    • Difficulty waking up or staying awake
    • Skin, lips, or nail beds appearing pale, gray, or blue