A New Influenza Variant is Surging, But Vaccination Remains Our Best Defense: WHO
The World Health Organization (WHO) has issued a warning about a rapidly spreading influenza variant, emphasizing the importance of vaccination as our primary defense. Dr. Wenqing Zhang, Head of the Global Respiratory Threats Unit at the WHO, reported that this year has seen the emergence and rapid expansion of a new AH3N2 virus subclade, known as J.2.4.1 or subclade K.
First detected in Australia and New Zealand in August, this variant has since been identified in over 30 countries. Despite concerns, Dr. Zhang reassures that current epidemiological data does not indicate an increase in disease severity, although the genetic shift represents a notable evolution in the virus.
Influenza viruses are known for their constant evolution, which is why vaccine compositions are regularly updated. The WHO, through its Global Influenza Surveillance and Response System (GISRS), tracks these changes, assesses associated risks to public health, and makes vaccine composition recommendations twice a year, in collaboration with global experts.
The new variant is not included in the latest vaccines produced for the Northern Hemisphere influenza season, but current seasonal vaccines continue to offer protection against severe diseases and reduce the risk of hospitalization, according to early evidence.
The WHO estimates that approximately one billion cases of seasonal influenza occur annually, including up to five million cases of severe respiratory illness. Up to 650,000 deaths each year are attributed to seasonal influenza-related respiratory disease.
Dr. Zhang emphasizes that vaccination remains our most effective defense, especially for high-risk populations and those caring for them. She shared preliminary estimates of the vaccine's effectiveness against the new variant, published in the United Kingdom, showing promising results.
The vaccine is approximately 75% effective against severe disease and hospitalization in children and around 35% among adults. Dr. Zhang warns that the upcoming holiday season may exacerbate respiratory illnesses, urging advanced planning and preparedness, including vaccination uptake and strengthened health system readiness.
The WHO advises countries to enhance lab diagnostics, year-round disease surveillance, and participation in the WHO GISRS surveillance network, which includes influenza centers in 130 countries and a dozen reference laboratories.
Global monitoring is crucial, and the WHO emphasizes the need for all countries to participate in surveillance, preparedness, and response for influenza and other respiratory viruses, as the next pandemic strain remains unknown. Dr. Zhang concludes that the time between the emergence of a new strain and its inclusion in vaccines can significantly impact the number of lives saved.
