2026年南半球流感季节使用的流感病毒疫苗的推荐成分

September2025 WHO convenes technical consultations1in February and September each year to recommend viruses forinclusion in influenza vaccines2for the northern hemisphere (NH) and southern hemisphere (SH) influenzaseasons, respectively. This recommendation relates to the influenza vaccines for use intheSH2026influenza season. A recommendation will be made inFebruary2026relating to vaccines that will be usedfor theNH2026-2027influenza season. WHO guidance for choosing between theNHandSHformulationsfor countries in tropical and subtropical regions is available on the WHO Global Influenza Programmewebsite3. National or regional authorities approve the composition and formulation of vaccines used in each country.National public health authorities are responsible for making recommendations regarding the use of thevaccine. WHO has published recommendations on the prevention of influenza4. Seasonal influenza activity From February through August 2025, influenza activity was reported in alltransmission zones.Overalldetections were higher compared to the same reporting period in 2024.The predominant viruses variedamong transmission zones and between countries. In Africa, influenza activity varied by transmission zone. In Northern Africa, influenza A activitydecreased and remained low during the reporting period, with more detections of influenza A(H3N2)viruses early in the reporting period, and more detections of A(H1N1)pdm09 viruses from June throughAugust. Throughout the reporting period,there was sustained influenza B virus activity, which was thepredominant influenza type from April onwards. InWestern Africa, influenza A viruses predominatedthroughout the reporting period, with a peak in late June and early July;most subtyped specimens wereA(H1N1)pdm09 viruses. InMiddle Africa, influenza detections remained low throughout the reportingperiod; influenza B activity was higher initially, but influenza A activity increased from June, with apredominance of A(H1N1)pdm09 viruses. InEastern Africa,influenza A and B viruses were detectedthroughout the reporting period with a predominance of influenza A which peaked in April. Amongsubtyped influenza A specimens, A(H1N1)pdm09 and A(H3N2) viruses co-circulated. InSouthern Africa,influenza activity peaked in May and June, with detectionsofalmost exclusively A(H3N2) viruses. In the Americas, influenza activity varied by transmission zone, although influenza A viruses accountedfor most detections and influenza B virus detections remained low throughout the reporting period in allzones. InNorth America, activity decreased from February andremained low throughout the rest of the reporting period. Among subtyped influenza A specimens, there was a slightly higher proportion ofA(H1N1)pdm09 virus detections compared to A(H3N2) virus detections. InCentral America andCaribbean, influenza activity decreased from mid-May onwards. Among subtyped influenza A viruses,A(H1N1)pdm09 and A(H3N2) viruses were detected at similar proportions through February, and fromMarch, A(H1N1)pdm09 virus detections predominated. InTropical South America, influenzaactivitypeaked in May. Influenza A viruses predominated with A(H1N1)pdm09 viruses accounting for the majorityof detections. InTemperate South America, influenza activity peaked in June. Influenza A viruses werepredominant with more A(H1N1)pdm09 detections. In Asia, influenza virus detections decreased during the reporting period in most transmission zones.Influenza A activity predominated in all transmission zones exceptCentral Asia. Most influenza detectionswere reported fromEastern Asia, whereactivity due to predominantly A(H1N1)pdm09 viruses peaked inFebruary, then remained low from mid-April. InSouth-East Asia, while influenza A viruses predominated,influenza B viruses were detected throughout the reporting period, with highest activity through March.Among influenza A viruses, A(H1N1)pdm09 viruses accounted for the majority of detections early in thereporting period, but A(H3N2) viruses predominated later in the reporting period. InSouthern Asia,influenza activity decreased from February but increased again between June and September. Influenza Avirus detections were predominant, though influenza B viruses were detected throughout the reportingperiod.Influenza A(H1N1)pdm09 detections decreased from February,while A(H3N2)detectionsremained predominant for the rest of the reporting period and increased in number from June. InCentralAsia, while influenza detections were low and predominantly influenza B viruses, no influenza detectionswere reported since May. InWestern Asia,influenza activity decreased early in the reporting period. Bothinfluenza A and B viruses were detected throughout the reporting period, with a higher proportion ofinfluenza A virus detections. Among subtyped influenza A specimens, A(H3N2) virus detections remainedhigher throughout the reporting period. In Europe, influenza activity due to influenza A and B viruses dec