The achievements of GISRS and WHO’s Global Influenza Programme since its inception, notably the timely response to the 2009 influenza pandemic, have been demonstrated and documented elsewhere (7, 10-11). However, it is worth outlining how GISRS and associated influenza surveillance systems have also significantly contributed to the response to COVID-19 pandemic, caused by a non-influenza respiratory virus.
National Influenza Centres were Crucial to Initial Laboratory Response During COVID-19
National Influenza Centres (NICs) are the backbone of GISRS, collecting clinical specimens from sentinel and non-sentinel sources in their country, testing them for influenza and other respiratory viruses, performing preliminary analyses on influenza viruses detected, and sharing representative specimens or viruses with WHO Collaborating Centres (CCs) for advanced antigenic and genetic analyses. NICs are designated by national Ministries of Health and recognized by WHO. Given the capacities and expertise in these laboratories of the GISRS network, they became COVID-19 testing centres in many countries early in the SARS-CoV-2 pandemic. As of July 2020, approximately 85% of over 220 national COVID-19 reference or testing laboratories globally were either NICs or closely associated with GISRS (12).
National Influenza Centres have Demonstrated Expertise of Virus Detection
The first External Quality Assessment Project (EQAP) for SARS-CoV-2, which was critical to ensure national capacity of laboratory detection of the novel virus, was undertaken through the GISRS annual influenza EQAP mechanism, coordinated by WHO’s GIP (13). A total of 233 laboratories (including 130 NICs) in 164 countries, areas, and territories participated, with the survey dispatched to labs from April to June 2020, despite disruptions caused by the pandemic. Overall, 94% of laboratories received a 100% pass rate. Of the 233 laboratories that participated in the SARS-CoV-2 EQAP, 68% (159/233) also participated in the influenza EQAP in 2019, indicating the substantial capacity for influenza testing that was utilized for testing during the COVID-19 response. Among laboratories that participated in the 2019 influenza EQAP, 94% of the labs scored 100% on the 2020 SARS-CoV-2 EQA.
Surveillance Data Generating and Sharing to Global Platforms
Data is key to understanding the dynamics of and informing the response to seasonal epidemics and pandemics. A key component of GISRS is the global data platform FluMart, in place since 1997, where countries report data on samples processed for influenza, such as the number of positive samples and subtype, on a weekly basis to a dataset called FluNet. Outputs of the data are visible to the public on WHO’s website (14). Since the emergence of SARS-CoV-2, WHO has requested that Member States regularly report counts of COVID-19 cases and deaths at different levels of aggregation for global situational awareness. FluMart formed the basis of the data collection platform for COVID-19 data (COVMart) since early in the pandemic. Globally, as of September 10, 2021, there have been 223,022,538 confirmed cases of COVID-19, including 4,602,882 deaths, reported to WHO through COVMart and displayed on the WHO COVID-19 dashboard (15).
Genomic Sequencing and Genetic Sequence Data Sharing
The sharing of virus genetic sequence data is essential, especially in the early stages of the response to an outbreak of a novel virus. Sequence data allows for the development of laboratory protocols to enable countries to detect and monitor novel viruses. GISAID (available at: https://www.gisaid.org/), which was launched in 2008 to enable rapid and open access to epidemic and pandemic influenza virus genetic data and associated clinical and geographical information through its EpiFlu platform, quickly became the host of the genetic sequence data of SARS-CoV-2. In fact, it published the first SARS-CoV-2 sequence data hours after it became available. GISAID has been an important partner of GISRS with confidence from countries for sharing their data through its data sharing mechanism. The development of the EpiCoV database and associated tools has been instrumental in the COVID-19 pandemic response. As of September 12, 2021, since the emergence of SARS-CoV-2, nearly 3.5 million complete genome sequences of SARS-CoV-2 have been uploaded to GISAID. About 80% of GISRS laboratories uploaded complete genome sequence data of SARS-CoV-2 to GISAID EpiCoV. In 2021, GISAID has also expanded to collect and share information on RSV, aside from influenza and SARS-CoV-2, though its EpiRSV data platform.