Foodborne pathogens may be making headlines, but there’s another highly contagious virus on the rise: coronavirus. It seems like a late summer COVID-19 wave is hitting the United States, with cases increasing in almost every state.
As of August 19, the U.S. Centers for Disease Control and Prevention estimates that cases are either on the rise or likely growing in 47 states.
Despite this, the CDC still classifies COVID activity as low nationally. Still, there’s a noticeable increase across the country—especially in the South and West.
In fact, Texas currently has the highest levels of COVID detected in wastewater among all states, according to CDC data.
This week, a school district in South Texas had to close for two days because of a rapid spread of COVID within its schools. San Perlita ISD announced the shutdown from August 25-26 to ensure the “health and safety” of students and staff, as noted in a statement released on Monday.
Experts suggest that this spike isn’t surprising. The SARS-CoV-2 virus can circulate year-round, but it has established a clear seasonal rhythm in the U.S. since the pandemic started.
“We’ve consistently seen two waves each year. One typically occurs in late summer, with another in the winter,” explains Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center.
While the public was concentrated on a sizable outbreak of cyclospora last month, COVID was also quietly creeping up. Data indicates that even if COVID isn’t the immediate concern for many Americans, it’s definitely spreading just as students prepare to head back to school.
Summer COVID-19 Surge 2026
According to experts, the U.S. is observing the start of this late summer COVID-19 wave. “The national data is starting to rise, but it isn’t a significant increase just yet,” Schaffner comments.
CDC’s latest analysis as of August 15 indicates that COVID activity in wastewater is still “very low” nationally.
However, data from WastewaterSCAN, a Stanford University-managed monitoring program, shows a “high” level of SARS-CoV-2 activity in wastewater across the nation, with a notable upward trend over the past 21 days.
“Since late June, we have witnessed a steady increase nationwide. So far this August, concentrations of SARS-CoV-2 have risen 106% compared to July,” says Amanda Bidwell, Scientific Program Manager of WastewaterSCAN.
The West and South are currently facing the highest levels, with California and Texas reporting the most significant jumps in cases.
As of August 17, at least 15 states and territories are experiencing active COVID outbreaks, according to a report by the Pandemic Mitigation Collaborative’s data tracker.
“This is concerning, especially if you’re in one of those areas,” remarks Michael Hoerger, Ph.D., an assistant professor at Tulane University.
Yet, experts point out that this wave seems to be less severe than previous years. For example, the U.S. experienced a significant summer surge in 2025 due to the “Stratus” variant that extended into fall.
“Currently, we are observing much lower concentrations of SARS-CoV-2 compared to this time last year,” Bidwell adds.
During the week ending August 13, approximately 5% of COVID-19 tests returned positive; this contrasts with over 9% at the same time last year, according to the CDC.
It’s still unclear just how severe this late summer wave could become or when it might peak. “We anticipate transmission to peak about a week into September,” Hoerger says, noting that the regional transmission may evolve as well.
Experts are cautious, observing that it remains peak vacation season in the U.S., and millions of children will soon return to classrooms, providing opportunities for the virus to spread.
“We need to be vigilant. It’s still mid-August,” Schaffner warns.
Current COVID-19 Variants in Circulation
The ongoing COVID wave is driven by a mix of known variants. Bidwell indicates that the dominant strain, XFG.1.1, accounted for 22-40% of all cases last month, per the latest CDC data.
XFG is a highly contagious recombinant variant that surpassed the Nimbus (NB.1.8.1) strain last summer, Dr. Albert Ko from Yale School of Public Health explains.
“It’s still closely related to previous omicron variants, which is likely why we aren’t seeing a significant peak this summer,” Ko adds.
According to CDC data, about 15% of cases are attributed to the BA.3.2 variant, known as Cicada. While this heavily mutated strain appeared earlier this year and has spread quickly globally, it hasn’t taken off in the U.S., experts note.
While major mutations haven’t been observed in the latest variants, Hoerger suggests they may evolve in the future.
“Just because we aren’t facing a novel variant doesn’t guarantee that COVID won’t lead to severe illness,” Ko cautions.
Symptoms of COVID-19 in 2026
The symptoms associated with the COVID-19 variants responsible for the current wave resemble those of other omicron strains. Symptoms can show up within two to 14 days after exposure.
Common symptoms of COVID-19 in 2026, according to CDC, include:
- Cough
- Sore throat
- Congestion
- Fatigue
- Fever
- Chills
- Shortness of breath
- Headache
- Nausea and vomiting
- Diarrhea
The symptoms of COVID and other respiratory viruses can be quite similar, which underscores the importance of testing.
If you receive a negative result from a rapid at-home antigen test, the CDC advises taking another test after 48 hours to be more certain you aren’t infected.
While most people recover from COVID-19 independently, Schaffner points out that some groups are more vulnerable to severe illness or hospitalization.
Higher-risk groups include adults over 65, infants, those with compromised immune systems or pre-existing conditions, and individuals who have never received a COVID vaccine.
Antivirals can be used to treat infections, potentially lessening symptom severity and duration if taken early.
COVID Quarantine Guidelines for 2026
If you become sick with COVID-19, the CDC recommends staying home and isolating yourself from others until you’re feeling better.
You can resume normal activities once your symptoms improve and you’ve been fever-free without medication for at least 24 hours, according to the CDC.
Experts suggest that while recovering, practicing social distancing—especially from immunocompromised individuals—and wearing a well-fitted N95 respirator or KN95 is wise.
Availability of the New COVID-19 Booster
For the past few years, COVID-19 vaccines have been reformulated to target the new strains emerging in the fall.
Earlier this year, the U.S. Food and Drug Administration approved recommendations for the updated COVID vaccine for the 2026-2027 season to specifically target the XFG variant, as reported by NBC News.
“The new vaccines will cover what is expected to circulate this fall and winter,” Schaffner notes.
These vaccines aren’t available yet, but experts predict their release sometime in September.
“If there’s any delay in the approval process, that could push the release back, which is frustrating given the current outbreaks,” Hoerger expresses.
Last year, the CDC changed its guidelines from a universal recommendation to a collaborative decision-making process for everyone aged six months and older.
“This means discussing vaccination with your healthcare provider, whether a doctor, nurse, or pharmacist,” explains Ko.
According to the CDC, the COVID vaccine helps protect against severe illness, hospitalization, and death. It also reduces the risk of developing long COVID, Hoerger adds.
Hence, most medical professionals recommend that everyone eligible receives a new COVID booster this fall, particularly for high-risk groups and pregnant women, as Schaffner notes.
“With many of us having been exposed to COVID multiple times, we’re building immunity. Still, there is a clear advantage to vaccination, especially before winter arrives,” Ko sums up.
