This dominant COVID-19 variant accounts for over 50% of cases, new CDC data shows

COVID-19 variant KP.3.1.1 accounts for more than half of positive infections in the United States, the latest projections from the Centers for Disease Control and Prevention (CDC) show.

The agency's Nowcast data tracker, which displays COVID-19 estimates and projections for two-week periods, reflected that the KP.3.1.1 variant accounted for 52.7% of positive infections, followed by KP.2.3 at 12.2% in the two-week stretch starting on Sept. 1 and ending on Sept. 14.

KP.3.1.1 first became the leading variant in the two-week period, starting on July 21st and ending on August 3rd.

"The KP.3.1.1 variant is very similar to other circulating variants in the United States. All current lineages are descendants of JN.1, which emerged in late 2023," Rosa Norman, a spokesperson at the CDC, previously told USA TODAY.

Previously, the KP.3.1.1 variant made up 40.0% of cases for the two-week period that started on Aug. 18 and ended on Aug. 31, and KP.2.3 accounted for 14.5%. According to the data, KP.3.1.1 rose 12.7%, and KP.2.3 decreased 2.3% from Aug. 31 in projected positive infections.

According to the CDC's Nowcast data, the following variants are in the top 10:

Can't see the table? Click here to view it.

Although not reflected on the CDC's Nowcast data tracker, a newly discovered COVID strain known as XEC continues to spread rapidly across multiple countries, including the U.S.

Scripps Research’s Outbreak.info page, last updated on Sept. 5, reported 95 XEC cases across 12 U.S. states and 15 different countries.

Here is the latest COVID-19 data in the U.S.

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COVID-19 Current Wastewater Viral Activity Levels Map

Note: Typically, wastewater data are updated weekly and the data that is published shows the results for the prior week. However, the results can take up to five days to a week to be published online. Thus, the data from Sept. 7 is considered the most recent data.

Here is a map of the states and territories that have reported wastewater viral activity levels. The data was published on Sept. 13.

Can't see the map? Click here to view it.

Here is a breakdown of the data that is shown in the map of the states and territories that have reported wastewater viral activity levels:

• Very High: 21 states

• High: 16 states

• Moderate: six states; two territories

• Low: two states

• Minimal: one state

• No Data: three states; one territory

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Changes in COVID-19 test positivity within a week

Data collected by the CDC shows that two Northeastern states and two territories that make up Region 2 had the biggest increase (+5.9%) in positive COVID-19 cases from Sept. 1, 2024, to Sept. 7, 2024.

The data was posted on Sept. 16.

Note: The CDC organizes positivity rate based on regions, as defined by the U.S. Department of Health and Human Services.

Here's the list of states and their regions' changes in COVID-19 positivity for the past week:

• Region 1 (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont): -0.1%

• Region 2 (New Jersey, New York, Puerto Rico, and the Virgin Islands): +5.9%

• Region 3 (Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia): -2.6%

• Region 4 (Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee): -1.2%

• Region 5 (Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin): -3.1%

• Region 6 (Arkansas, Louisiana, New Mexico, Oklahoma, and Texas): -2.6%

• Region 7 (Iowa, Kansas, Missouri, and Nebraska): +0.5%

• Region 8 (Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming): -0.9%

• Region 9 (Arizona, California, Hawaii, Nevada, American Samoa, Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Guam, Marshall Islands, and Republic of Palau): -3.4%

• Region 10 (Alaska, Idaho, Oregon, and Washington): -1.2%

The CDC data shows COVID-19 test positivity rate was recorded at 14.9% from Sept. 1 to Sept. 7, an absolute change of -1.6% from the prior week.

COVID-19 symptoms

The CDC has not said if the different variants have their own specific symptoms. The government agency outlines the basic symptoms of COVID-19 on its website. These symptoms can appear between two and 14 days after exposure to the virus and can range from mild to severe.

These are some of the symptoms of COVID-19:

• Fever or chills

• Cough

• Shortness of breath or difficulty breathing

• Fatigue

• Muscle or body aches

• Headache

• Loss of taste or smell

• Sore throat

• Congestion or runny nose

• Nausea or vomiting

• Diarrhea

The CDC said you should seek medical attention if you have the following symptoms:

• Trouble breathing

• Persistent pain or pressure in the chest

• New confusion

• Inability to wake or stay awake

• Pale, gray, or blue-colored skin, lips, or nail beds

COVID-19 vaccines

The CDC recommends that everyone 6 months old and older get the updated 2024-2025 COVID-19 vaccine. Norman also recommends that the elderly and those who are immunocompromised should get vaccinated in order to protect themselves from COVID-19.

"At this time, we anticipate that COVID-19 treatments and vaccines will continue to work against all circulating variants," Norman said. "CDC will continue to monitor the severity of variants and will monitor vaccine effectiveness."

Contributing: Anthony Robledo, USA TODAY

Ahjané Forbes is a reporter on the National Trending Team at USA TODAY. Ahjané covers breaking news, car recalls, crime, health, lottery and public policy stories. Email her at [email protected]. Follow her on Instagram, Threads and X (Twitter) @forbesfineest.

This article originally appeared on USA TODAY: COVID-19: A look at variants, latest CDC data, and symptoms