On 30 March 2026, the World Health Organization Regional Office for South‑East Asia (WHO SEARO) convened a regional webinar that brought together experts from WHO’s Global Influenza Programme (GIP), WHO Country Offices, National Influenza Centres (NICs) in SEAR Member States and WHO Collaborating Centres for Influenza Research and Reference (WHOCCs) in Melbourne and Tokyo. The session focused on reviewing recent developments in influenza surveillance, virological trends and the global vaccine composition determination process, with particular attention to the 2026 Southern Hemisphere vaccine and the 2026–2027 Northern Hemisphere vaccine.
The discussion highlighted the continued importance of strong coordination across global, regional, and national levels to ensure that influenza surveillance systems remain responsive, resilient, and aligned with evolving influenza virus characteristics and global risk assessments.
Participants of the Regional webinar. Photo credit PEM/WHE/SEARO
Operating in a Complex and Changing Environment
Opening the session, Dr Nilesh Buddha, Regional Emergency Director (RED) and Acting Director of Programme Management (DPM) at WHO SEARO, emphasized that influenza surveillance systems are increasingly operating under complex conditions, including financial constraints and competing public health priorities. Despite these challenges, countries across the region have maintained strong performance on key surveillance indicators and have continued regular and consistent reporting, reflecting both resilience and sustained commitment. Sustained high performance and timely reporting remain essential for the early detection of influenza activity, supporting global risk assessments and preparedness efforts for seasonal, zoonotic, and pandemic influenza.
Dr Nilesh Buddha, the Regional Emergency Director provided the opening remarks. Photo credit – PEM/WHE/SEARO
Performance of Influenza surveillance in SEAR and areas for further Improvement
The webinar underscored that influenza surveillance is not merely the collection of data, but a system that generates systematic and ongoing information to guide public health action at national, regional and global levels.
By integrating genetic, antigenic and serological data, countries contribute critical evidence that informs vaccine composition decisions and global risk assessments. In this context, Member States are not passive but active contributors to the evidence generation process within a highly interconnected Global Influenza Surveillance and Response System.
Recent surveillance data presented during the webinar demonstrated clear and consistent seasonal influenza patterns across the region. Most countries continue to meet the WHO‑recommended testing threshold of at least 50 samples per week at the national level, although some inter‑country variability persists. National influenza Centres generally demonstrate high diagnostic performance, as confirmed through external quality assurance mechanisms. However, the systematic and continuous reporting of unsubtyped influenza viruses, particularly influenza A, in some countries remains an important area requiring further strengthening.
Virological analysis showed the diverse circulation of influenza viruses including A(H3), A(H1N1), and influenza B with notable variation observed across countries. The robust influenza surveillance systems in the region also demonstrated their sensitivity in detecting zoonotic spillover events, with human infections caused by avian influenza A(H5N1) reported in countries such as Bangladesh and India.
At the same time, the emergence of new variants such as the recently detected H3 clade K reinforces the need for continuous monitoring through influenza surveillance, genomic sequencing of representative samples, and timely reporting to the public domain to support regional and global action.
Regional efforts to improve laboratory diagnosis, WHO (GIP) coordinated External Quality Assurance Programme (EQAP) and country‑led targeted capacity‑building initiatives have contributed to the continuous strengthening of laboratory capacity and enhancement of diagnostic quality at NICs across Member States.
Mr. Haytham Mohammad of WHO SEARO, provided the regional epidemiological and virological update on influenza. Photo credit PEM/WHE/SEARO.
Timely detection, verification and analysis of public health events including Influenza
The importance of the rapid reporting of non‑seasonal influenza subtypes under the International Health Regulations (IHR) was strongly emphasized by the Health Information Management Unit of WHE/SEARO. In accordance with the IHR (2005), countries are required to notify WHO within 24 hours of any event that may constitute a public health risk, including human infections caused by new influenza subtypes.
A significant proportion of signals are now detected through event‑based surveillance systems, including media monitoring and other informal sources. Improved and increased detection of these signals underscore the need for countries to ensure rapid verification, analysis and timely reporting, in order to initiate timely public health responses to and maintain effective national, regional and global situational awareness of potential public health threats.
The webinar also highlighted advances in data systems, particularly the Public Health Intelligence Dashboard. While the Influenza Programme maintains its own dashboards under the Global Influenza Strategy (2019–2030), the Public Health Intelligence Dashboard integrates multi‑disease data including influenza into a single platform to support emergency response decision‑making. By enabling real‑time visualization and country‑level analysis, the dashboard enhances accessibility to integrated data/evidence and supports well – informed and timely decision‑making across all levels of health system.
The Critical Role of influenza Virus Sharing
A central theme of the discussion was the importance of timely and representative virus sharing. Samples submitted by National Influenza Centres (NICs) to WHO Collaborating Centres undergo detailed genetic, antigenic and serological analyses, forming the foundation for the global understanding of circulating influenza viruses.
These analyses directly inform vaccine composition decisions. As emphasized during the session by Dr Patrick Reading, Director of the Victorian Infectious Diseases Reference Laboratory (VIDRL) in Melbourne, the value of virus samples depends heavily on their timeliness and representativeness, with recent, well‑characterized specimens providing the most actionable insights.
Dr Patrick Reading, Director VDRL Melbourne, provided updates on the Southern Hemispheres vaccine composition determination process. Photo credit PEM/WHE/SEARO
Informed Decision making at influenza Vaccine Composition meetings
Dr Magdi Samaan from WHO Headquarters (GIP) highlighted how global data is translated into vaccine recommendations. He emphasized that these decisions rely on the integration of surveillance data, genomic sequencing and laboratory analyses, ensuring that recommendations are grounded in the most comprehensive and up‑to‑date evidence available. Timely and high‑quality data inputs from countries are therefore essential to ensure accurate vaccine strain selection and to support effective protection of populations worldwide.
Dr Magdi Samaan, WHO, HQ – GIP, provided updates on the Northen Hemisphere Vaccine Composition Determination. Photo credit PEM/WHE/SEARO
Resilience of influenza surveillance in Challenging Contexts in SEAR: Myanmar experience
Myanmar’s experience, as presented by Dr Yee Mon Mya, demonstrated that influenza surveillance can be sustained even in challenging operational environments. Despite conflict, logistical constraints and limited human resources, the country has continued to maintain surveillance through adaptive strategies, including the expansion of sentinel sites and the use of flexible implementation approaches.
This example underscores the importance of designing surveillance systems that remain functional and resilient under real‑world conditions.
Dr Yee Mon Mya, WHO country office for Myanmar, shared Myanmar experience in strengthening influenza surveillance activities and virus sharing with the WHO CC – Tokyo, Japan. Photo credit PEM/WHE/SEARO
Looking Ahead: Key Priorities
The webinar concluded with a clear set of priorities for strengthening the regional influenza surveillance systems. These include improving consistency in testing, particularly influenza subtyping and reporting, enhancing the completeness of laboratory data and ensuring timely and representative virus sharing with WHO.