Influenza virus sharing is vital to global preparedness to facilitate pandemic risk assessment, develop candidate vaccine viruses, update diagnostic reagents and test kits, and determine resistance of influenza viruses to antiviral medicines. In WHO's South-East Region, National Influenza Centres (NICs) have long shared viruses with WHO Collaborating Centres (CCs) as part of their routine influenza surveillance activities. But their efforts were severely disrupted during the COVID-19 pandemic, especially during the early stages as staff and resources across the surveillance system were diverted to support an emergency response.
Specific challenges included: a lack of influenza positive samples; poor geographical or temporal representativeness of collected specimens (especially during periods of lockdown); and excessive workloads, which caused delays in influenza testing (so specimens may have been collected but they were not processed) and created operational difficulties in isolating viruses for shipment. Specimen collection media (viral transport medium) also posed a challenge during the pandemic as the transport medium used for SARS CoV-2 was not appropriate for influenza.
In those countries that quickly resumed influenza surveillance to pre-COVID-19 levels, an additional challenge was the very low transmission of seasonal influenza seen during the pandemic, which resulted in low numbers of specimens shared.
In an effort to re-prioritize virus sharing in the region, participants at two regional influenza meetings shared their experiences of influenza surveillance during the pandemic, discussed the latest WHO guidance for adapting influenza surveillance systems to also monitor SARS-CoV-2 and considered a range of context-specific needs and priorities. Their deliberations led to four key recommendations:
- Expand influenza surveillance to non-sentinel sites, with subsequent reporting to FluNet, to increase the chances of identifying influenza activity and collecting samples for testing and virus isolation.
- Advocate for integrated influenza and SARS CoV-2 surveillance, including the use of multiplex kits.
