Here are the latest national COVID-19 trends, according to the U.S. Centers for Disease Control and Prevention (CDC) and major wastewater surveillance providers:
- About 0.9 in every 100,000 people were hospitalized for COVID-19 during the week ending May 17.
- COVID-19 test positivity declined slightly, from 2.8% of COVID-19 tests returning positive results during the week ending May 17 to 2.7% during the week ending May 24.
- SARS-CoV-2 concentration in wastewater has decreased 7% between the week ending May 17 and the week ending May 24, and the national wastewater viral activity level is “very low,” per the CDC.
- SARS-CoV-2 concentration in wastewater has decreased 9% between May 14 and May 21, and the national wastewater trend is “low,” per WastewaterSCAN.
Everyone in the COVID-tracking space is watching for a summer surge. Disease levels in the U.S. remain on the lower end as of late May, but I see warning signs for potential increases soon: cases are going up in some West Coast states, and new variant NB.1.8.1 has reached the U.S.
National averages for SARS-CoV-2 levels in U.S. wastewater were still slowly declining, in the most recent data from the CDC, WastewaterSCAN, and Biobot Analytics. WWSCAN’s weighted national average for mid-May has actually dipped below the lowest level that this metric reached last spring, at under 100 (in WWSCAN’s normalized units) in the last two weeks of data. Still, recent averages remain several times higher than the true low levels we experienced in 2021 and 2022.
While COVID-19 decreases persist across most regions, some West Coast and South states continue to report increased disease levels. The CDC reports growing SARS-CoV-2 in wastewater and increased COVID-19 test positivity in states such as California, Oregon, and Washington. Notably, viral levels in Hawaii appear to have stabilized at a higher plateau after increasing in the last month.
The agency’s disease forecasting center estimates that, as of May 27, COVID-19 cases are “growing or likely growing” in six states: Washington, California, Florida, Tennessee, North Carolina, and Massachusetts. Cases are “declining or likely declining” in 17 states, mostly across the Midwest and Northeast, and “not changing” in 22 states, per the center.
A newer variant, called NB.1.8.1, is contributing to increased COVID-19 spread internationally. The World Health Organization (WHO) published an outbreak notice about this variant on May 28, noting higher test positivity in the Southeast Asia, Western Pacific, and Eastern Mediterranean regions. Global test positivity, as estimated by the WHO, has reached levels not seen since last summer; though the notice cautions that COVID-19 surveillance is limited.
NB.1.8.1 recently arrived in the U.S., but it will be a few weeks before this variant takes over. The CDC had identified fewer than 20 cases as of late May, per reporting in TODAY. Remember, all COVID-19 data in 2025 are reported with significant delays, so it’s very possible that this variant is causing new outbreaks that haven’t made it into public health reporting yet.
Meanwhile, confusion and concern continues about vaccines. Despite Health Secretary Robert F. Kennedy Jr. announcing last week that COVID-19 vaccines would no longer be recommended for children and pregnant people, the CDC has continued to include these shots in its vaccine guidance. The People’s CDC has more details about recent developments and how to push back.
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