The spread of COVID-19 is picking up speed this summer in the US. The key indicator of the virus shows that it's becoming more active, according to the latest data released by the Centers for Disease Control and Prevention (CDC). How Are The Levels Of COVID Being Measure? The CDC has a great way of tracking viruses: by checking our wastewater. This is a very helpful tool because it can find signs of the virus spreading in a community even before people start feeling sick and go to the doctor. In a recent update, the CDC reported that the amount of COVID-19 found in wastewater across the country has gone up from a "low" level to a "moderate" level. This is a clear sign that the virus is becoming more common. The data also shows that the highest levels of the virus are currently in the Western part of the country. States like Alaska, California, Colorado, Nevada, and Utah are seeing the most activity. If you live in one of these areas, it's a good idea to be a little more careful, as the risk of getting infected is higher. Other data also confirms the increase in cases. As of Tuesday, the CDC estimates that infections are growing or likely growing in 45 states, a jump from 40 states the previous week. This late-summer rise is being driven in part by a new variant, XFG, or "Stratus," which is now the third-most common strain in the U.S. The variant was first found in Southeast Asia in January but didn't become a major presence in the U.S. until May. By late June, it was estimated to account for up to 14% of cases. What Is The Current Strain Of COVID Affecting The US? The World Health Organization explains that a new COVID-19 variant, called XFG, is now being watched closely by health experts around the world. Gavi vaccine alliance explains that Two new variants are now getting attention from scientists: NB.1.8.1, nicknamed "Nimbus," and XFG, nicknamed "Stratus." Both variants are spreading very quickly. Since early 2025, they have spread across the globe. For example, XFG accounted for 25% of cases in Europe by late May, while NB.1.8.1 was at 11% in late April. However, despite their rapid spread, experts say there's no evidence that these variants cause more severe illness, hospitalizations, or deaths than other versions of the virus. XFG ("Stratus") is good at evading our immune system. It has specific mutations that help it dodge antibodies, making it harder for our bodies to fight off. However, it doesn't seem to be as good as NB.1.8.1 at infecting cells. Is Stratus COVID Strain Dangerous? WHO explains that the number of XFG cases is rising around the world. It’s now found in 38 countries and is growing quickly, especially in parts of Asia, the Americas, and Europe. In some countries, like India, XFG has become the main variant. Despite this increase, experts believe the global risk of XFG is low. Early data suggests that this variant doesn’t cause more severe illness or lead to more deaths than other variants currently spreading. Do Vaccines Work for Stratus COVID Strain? Experts believe that the current COVID-19 vaccines will still be effective against XFG. They are expected to protect people from getting seriously sick or needing to go to the hospital. While some countries in Southeast Asia have seen more cases and hospitalizations at the same time as XFG became more common, it's not clear if the variant itself is causing this. It's too early to say for sure how big this new wave of cases will get. What Are The Key Symptoms of Stratus? Doctors have reported that a standout symptom some patients with XFG have experienced a "hoarseness" feeling of scratchiness in their throat. Other symptoms include common issues like fever, chills, dry cough, fatigue, muscle ache, nasal congestion, nausea, vomiting or diarrhea.Although XFG is spreading quickly, it doesn't appear to be more dangerous. The WHO continues to monitor them closely to see if that changes.