COVID-19 cases are rising across all 50 US states during an unexpected summer surge, according to figures released by the Centers for Disease Control and Prevention.
Estimates published by the national public health agency on August 12, 2026, show that infections are growing or likely growing in all 50 states, with zero states reporting a decline or stable trend.
"As of August 12, 2026, we estimate that COVID-19 infections are growing or likely growing in 50 states, declining or likely declining in 0 states, and not changing in 0 states," the CDC said in its statement.
Although COVID-19 is typically thought of as a winter virus alongside influenza and respiratory syncytial virus (RSV), health experts are tracking increased infection rates despite the warm weather. The highest spikes in cases are currently concentrated in southern and western states, with California and Texas among the hardest hit.
Despite the nationwide increase in transmission, the CDC reported that the weekly percentage of emergency department visits attributed to COVID-19 remains very low, at just 0.3 percent. Overall respiratory illness levels across the country also remain low.
Contrasting Wastewater Data and Strain Tracking
Public health officials increasingly rely on municipal wastewater tracking to monitor viral activity because fewer people undergo clinical testing than during the height of the pandemic. However, surveillance sources currently present differing assessments of the outbreak.
According to CDC data from August 8, 2026, the national level of COVID-19 activity in wastewater is ranked as very low. In contrast, data from WastewaterSCAN, an infectious disease monitoring program run by Stanford University in California, showed that COVID-19 activity in wastewater is high across the US, with an upward trend over the past three weeks.
The dominant variant spreading across the nation is XFG.1.1, which accounted for 22 to 40 percent of all COVID-19 cases in July, according to the CDC. Health officials note the strain is more contagious than previous variants but does not appear to cause more severe illness.
Overall test positivity rates also remain lower than at the same point last year. Last week, about four percent of COVID-19 tests came back positive, compared with more than nine percent at the same time in 2025.
Seasonal Trends and Vaccination Guidance
Health experts are not surprised by the increase in cases toward the end of summer, noting that a similar pattern emerged in August 2025. Researchers believe COVID-19 may have settled into a regular seasonal cycle.
"If you look back over the last few years.. the lowest rates across the country are usually late June, early July, and then in August you start to see this increase in rates," Dr Susan Kline, professor in the division of infectious diseases and international medicine at the University of Minnesota, told HuffPost.
"And last year there was actually a peak in late August, going into mid-September. And we don't know for sure if that's going to be replicated this year, but it is a possibility," Dr Kline added.
Medical experts emphasize that the current wave of infections appears less severe than those in previous years. To maintain protection, the CDC recommends COVID-19 vaccination for everyone six months of age and older, stressing that staying up to date with vaccines is a "more reliable way to build protection" against the illness than contracting the virus.
However, recent survey data shows growing vaccine hesitancy. Since October 2025, the number of people who state they will probably or definitely not get vaccinated has increased.
COVID-19 Symptoms and Isolation Rules
People infected with COVID-19 can experience a wide range of symptoms, ranging from mild discomfort to severe illness. Symptoms generally appear between two and 14 days after exposure to the virus, often starting mild before progressing.
Common symptoms in 2026 include a cough, sore throat, congestion, fever, shortness of breath, headache, nausea, vomiting, diarrhea and fatigue.
While most patients recover on their own, those at the highest risk of developing severe illness include adults aged 65 and older, people with weakened immune systems, and individuals who are unvaccinated. The infection can be treated with antiviral medications, which help reduce the severity and duration of symptoms when taken early in the course of illness.
To prevent further transmission, the CDC recommends staying home and away from others until symptoms have improved and you have been fever-free for at least 24 hours without using fever-reducing medication.
