Aggressive Flu Strain Sparks Alarm: UK Battles Severe Virus Wave—Is Israel Next?

A new, highly infectious mutation of the influenza virus is causing an early and severe wave of illness in the United Kingdom, raising concerns among health officials in Israel. British authorities are warning of what local media describes as potentially the “most severe flu season on record,” following the emergence of an unusual mutation in the A(H3N2) strain that has made the virus particularly aggressive.

The latest weekly report from the UK Health Security Agency (UKHSA) points to a flu season starting earlier and stronger than usual, with a sharp increase across all indicators: the percentage of positive flu tests has reached 11.6%, and hospital admissions have climbed to 3.81 per 100,000 residents, a metric typically seen only in December. This surge is combined with a worrying rise in the RSV virus, particularly among children under five. The UK is currently anticipating a potential "quad-demic" wave involving four winter viruses: Flu, RSV, Norovirus, and COVID-19.

Israeli Experts Issue Cautionary Assessment

Israeli health experts are closely monitoring the developments, as such a combined surge could severely strain healthcare systems. However, while acknowledging the seriousness, they urge calm.

Professor Ran Balicer, Deputy Director-General and Chief Innovation Officer at Clalit Health Services, and Professor of Public Health at Ben-Gurion University, emphasized that although the strain has undergone changes, the current vaccine remains effective.

He noted: “A number of changes have occurred simultaneously, and this is creating concern in the UK for a larger-than-usual wave of infections, but there is no certainty to cling to. Healthcare systems take into account the ability of the flu virus to change every winter."

Professor Balicer stressed that the vaccine’s efficacy against this mutated strain, while partial, is still significant: “According to the data from the UK, even though the strain has undergone changes, the vaccine is still effective and prevents a significant part of the complications of the disease.” He pointed out that the flu vaccine prevents about half of all hospitalizations, which is a critical rate, especially for at-risk groups such as the elderly, infants, and those with chronic illnesses.

The Travel Factor and Predicted Arrival

Dr. Ilan Yehoshua, Director of the Family Medicine Department in the Southern District of Maccabi Health Services, stated that the outbreak in the UK is “definitely a cause for concern for us in Israel.”

He explained the high risk factor: “This is because it is a country that tens of thousands of Israelis fly to frequently.” Dr. Yehoshua warned that the arrival of the British mutation is likely a matter of time, especially since other winter viruses, including RSV, are already circulating in Israel.

Both experts stressed that despite the mutation, the core defense remains vaccination. Dr. Yehoshua advised the public to take precautions, especially regarding travel and hygiene: “Influenza symptoms are characterized by a fever above $38.5, muscle aches, and headaches, not just a runny nose and cough. The solution is simply to get vaccinated, follow hygiene instructions, and be careful, with an emphasis on flights and visits to countries around the world, ventilating closed spaces, not coming to work sick, and so on.”