The World Health Organization assessed that the global risk from this variant is low, but data indicates a sharp rise in cases in recent months. However, in Israel, the infection rate remains lower.
New COVID-19 variant NB.1.8.1 spreads globally, cases confirmed in Russia and US. Illustration.(photo credit: Freer. Via Shutterstock)ByDR. ITAY GALAUGUST 10, 2025 01:57Updated: AUGUST 10, 2025 07:29
COVID is back: The new XFG variant, known as “Stratus,” is rapidly spreading across the US and many European countries, becoming one of the prominent mutations of the summer.
The World Health Organization (WHO) has assessed that the global risk from this variant is low, but data indicates a sharp rise in cases in recent months. However, in Israel, the infection rate remains much lower, with only a few dozen new cases reported in the past week. Experts warn, though, that the pandemic is no longer following the traditional “winter illness” pattern.
The XFG variant was first detected in January in Southeast Asia, and for several months, it was nearly unnoticed in the West. In the United States, for example, it accounted for less than 1% of confirmed cases until May, but by the end of June, it rapidly surged to 14% of diagnosed cases, making it the third most common variant after NB.1.8.1 and LP.8.1. European countries are reporting similar trends, with rising infection rates in the UK, France, Germany, Spain, and Italy, along with hotspots in Belgium, the Netherlands, Portugal, and Sweden.
The WHO has added the new variant to its official monitoring list but has also noted that current vaccines are expected to offer protection, both against symptomatic illness and severe disease. According to researchers, XFG is a combination of two previous variants—F.7 and LP.8.1.2—which gives it some ability to evade the immune system, but it is likely not as contagious as other dominant omicron variants.
New variant doesn’t follow usual pattern of viral diseases
What interests experts is that the infection is not following the usual patterns of viral diseases.
In the past, COVID surges were generally seen during the winter months, similar to the flu and cold viruses, but recent experience shows that the virus can emerge even during the summer. The reasons for this are still not fully understood, and they may be linked to changes in the virus’s structure, human behavior during different seasons, or gaps in population immunity.
According to the Health Ministry’s data, only a small number of new cases have been recorded in the past week in Israel, indicating a slight rise but still a very low infection rate compared to the US and parts of Europe. Nonetheless, experts recommend continued monitoring and preparation for a scenario where infection rates may rise.
The symptoms of the “Stratus” variant are not significantly different from those of recent COVID strains. The most common symptoms include fever or chills, cough, shortness of breath, sore or irritated throat, runny nose or congestion, loss of taste or smell, fatigue, muscle or joint pain, headache, and nausea. Some patients have also reported hoarseness. In more severe cases, immediate medical attention is needed if there is difficulty breathing, chest pain or pressure, sudden confusion, inability to wake up, or changes in the color of the lips, nails, or skin.
The Centers for Disease Control and Prevention (CDC) notes that it is closely monitoring infection rates, but due to reduced reporting from states, data updates are now being provided less frequently. According to global data, the infection rate of XFG jumped from 7.4% in early May to 22.7% by the end of the month across 38 countries, showing the variant’s potential for rapid spread.
While the overall public health risk is assessed to be low, the fast spread of “Stratus” demonstrates that the COVID virus continues to surprise the world and change its form, even five years after the pandemic began. In Israel, the infection rate remains low for now, but as we have learned, COVID can quickly adapt, spread, and cause widespread illness, particularly during peak travel seasons.
The coronavirus can cause around 200 possible symptoms, but urgent medical attention is required in certain cases where the condition may suddenly worsen, especially in chronic patients, the elderly, pregnant women, and infants. Warning signs of severe illness include difficulty breathing or trouble finishing a sentence, chest pain or pressure, sudden confusion, trouble waking up or staying awake, changes in lip, nail, or skin color to a bluish-gray or pale hue, a fever lasting more than three days, frequent vomiting, not urinating for more than 10 hours, or unexplained skin bleeding that doesn’t fade when pressed.