GLOBAL INFLUENZA HOSPITAL SURVEILLANCE NETWORK:
LINKING EPIDEMIOLOGICAL AND CLINICAL DATA TO VIROLOGICAL INFORMATION

OBJECTIVE

The Foundation for Influenza Epidemiology seeks to support hospital-based sentinel surveillance sites that can improve our understanding of influenza epidemiology and other respiratory viruses and contribute to the WHO’s vaccine strain selection process by monitoring influenza virus circulation and hospital-associated disease burden as part of the Global Influenza Hospital Surveillance Network (GIHSN).

We are looking for not-for-profit institutions with experience in hospital-based surveillance for influenza and other respiratory viruses that would be willing to participate in the GIHSN using a standardized protocol for case ascertainment and respiratory sample collection.

The Global Influenza Hospital Surveillance Network (GIHSN) is a platform that collects standardized data from hospitalized patients with severe acute respiratory illnesses across countries, including low-, middle-, and high-income countries from both hemispheres. Twenty-five sites and 100+ hospitals in 23 countries have participated in the GIHSN in 2025-2026.

The GIHSN has evolved over the last 13 years to focus on linking epidemiologic and clinical data with Whole Genome Sequencing (WGS) information to facilitate exploring viral phenotypes as they relate to disease severity and/or vaccine breakthrough cases. This information is shared with local public health authorities, the World Health Organization (WHO) and the scientific community at large.

The GIHSN is the largest network of its kind and is currently scaling up. A Memorandum of Understanding with WHO was established in 2023 to strengthen collaboration with GISRS (Global Influenza Surveillance and Response System).

Although influenza surveillance is critical for GIHSN, the network supports sites to include other respiratory viruses as part of their surveillance. Rapid sharing of surveillance data is important to improve our understanding of respiratory virus circulation, evolution and associated burden. These can be used to guide public health decision making in cases of epidemics and healthcare surge capacity. Data on virus genomic evolution can also guide improvements to vaccine-strain selection.

The following specific objectives are underscored in this Call for Proposals 2026-27:

• Year-round surveillance (from November 1st, 2026, to October 31st, 2027).
• Systematic screening and enrolment of hospitalized patients with respiratory illness meeting protocol case definition1.
• Collection of epidemiologic and clinical data for all participating patients, using a standardized questionnaire administered at enrolment and chart abstraction at patient discharge (or death) to collect clinical outcomes.
• Enrolled patients would have respiratory specimen collected shortly after hospital admission (within 32 hours from admission date) and sent for testing at the local and/or reference laboratory or National Influenza Centre in the country.
• RT-PCR tests for influenza should be done for all patients enrolled as a priority.Multiplex PCR and/or wet assay for SARS-CoV-2, RSV and other respiratory viruses is a strong added value.
• Storage (-20C or -70C) of respiratory specimens (e.g. nasal-pharyngeal swabs) from all enrolled patients for a minimum of one year. This will assure sample availability for additional retrospective investigations, pathogen discovery research, or evaluation of new diagnostic tool if necessary.
• Whole Genome Sequencing of a minimum of 100 influenza viruses will be expected. If number of influenza positive cases are lower than that, sites are encouraged to complete the required number of virus whole genome sequencing (WGS) data using SARS-CoV-2 and RSV positive cases. WGS data will be uploaded to GISAID (Global Initiative on Sharing All Influenza Data) by each site in a reasonable timeframe so that results are available for the WHO Vaccine Composition Meeting (VCM) which occurs twice a year, reflecting the seasonality of influenza viruses in the Northern and Southern Hemispheres.

BENEFICIARIES’ ELIGIBILITY CRITERIA

Applicants should be not-for-profit institutions and will be asked to provide substantiating documentation when submitting their application.(See How to apply)

All sites must show an excellent connection between a hospital surveillance platform and a virology laboratory in their country, allowing for influenza testing by RT-PCR and subsequent sequencing (subtype/lineage) of the positive specimens within 7 days from sample collection.

If a site has no capacity to generate WGS, the site is offered the possibility to ship its specimens to the GIHSN sequencing platform at the National Influenza Centre in Lyon, France, or to another GIHSN partner having sequencing capacity and located closer to the site, under the Terms of Reference for sharing materials in GISRS. Shipment expenses will be borne by the GIHSN.

All sites must have the capacity to submit WGS at a minimum consensus data of the HA and NA segments to the GISAID EpiFlu™ database. Clinical information should be captured in the current questionnaire used by the GIHSN (possibly e-CRF) including clinical outcomes, and the link with GISAID sequence.

Sites who have collaborated with GIHSN over the years are strongly encouraged to re-apply. Current European sites in the GIHSN system will be leveraged for the European pilot initiative.

SELECTION PROCESS

Applications from Institutions meeting the eligibility criteria will be reviewed and evaluated by the Independent Scientific Committee of the Foundation according to predefined quality criteria.

Main evaluation criteria are:

• Description of study settings: Clear description of the surveillance population and settings, number of hospital facilities, link with a virology laboratory with testing capacity (see below), whether data are shared with the National Influenza Centre in the country, or WHO reference centres.
• Laboratory capacities: Availability of RT-PCR testing for influenza viruses, including subtyping for influenza A and lineage for influenza B. The existing full genome sequencing capacities on site or proposed referral system to sequence influenza viruses (or SARS-CoV-2) should be described. Sites should mention if they will test samples for other respiratory viruses and, if so, describe the strategy for testing (e.g., all samples tested for all viruses, including influenza and SARS-CoV-2 or a random subset of samples tested for other respiratory viruses after influenza testing is done, or other options).
• Surveillance period: Sites are expected to run the surveillance year-round (from November 1st to October 31st the following year). If expected number of cases to be screened is too high to be handled, site should explain a strategy to systematically assess patients over the surveillance period. See suggested Sampling Strategy in Appendix 3.
• Targeted sample size for WGS: The estimated number of sequenced samples expected to be shared via the GISAID platform during the season is at minimum 100 and will depend on the site’s capacity and number of cases identified as associated with influenza viruses and/or SARS-COV-2. If site proceeds with sequencing of other respiratory viruses, results can be shared in the GIHSN, but cost will not be covered by the GIHSN grant.
• Clinical information data collection capacities: The proposal needs to include detailed description about the way the site will identify eligible patients, their local staff capacity to interview and collect information from charts (please indicate if electronical medical chart abstraction will be done), and whether they expect to collect clinical and respiratory samples from all patients or propose a sampling frame if the expected number of patients to be screened is too high to be handled. The sampling scheme should be focused on influenza surveillance. Other respiratory viruses can be incorporated in the same sampling frame according to resources available and/or use of multiplex testing tools in a subset of patients. Sites that can generate information for other respiratory viruses (especially SARS-CoV2 and RSV) will be strong applicants, to ensure global monitoring and awareness of respiratory virus circulation. Applicants should clearly describe their proposal screening, enrolment, and testing strategies, including if testing for other respiratory viruses will be performed, and how they can meet the year-round surveillance requirements. This should consider local capacity and resources. See suggested Sampling Strategy in Appendix 3.
• Sites willing to apply to participate in the European initiative (see above) will need to demonstrate that their country has a mature influenza vaccination program in place, and that they have the capacity to collect robust data at patient level, including patient’s influenza vaccination status (ideally using vaccine registries if existent), as well as the capability to perform WGS – particularly in specimens collected from vaccine breakthrough cases. Strengthening these capacities across participating centres will therefore be an important prerequisite for site consideration.
• Timelines of the data availability: Sites should be able to upload data from the questionnaire using the e-CRF or through regular uploads using excel files to share data on enrolled patients (regardless of test results). The preferable approach should be clearly described in the proposal. If sharing data by excel batches, data would be expected to be uploaded every last Wednesday of each month.

• Sites with sequencing capacity should upload genome sequencing data in GISAID as soon as they have results available. Sites using the GIHSN sequencing platform or another GIHSN partner with sequencing capacity should be able to have their samples shipped in regular batches along the year-round surveillance and at least a minimum of 4 weeks before each WHO strain selection meeting (February and September each year). The proposal should describe the site’s ability to manage data uploads and shipments and expected timelines for shipments. If the suggested timelines for data sharing or sample shipments cannot be met, site should explain the rationale.

• Cost-effectiveness: the relevance of the cost in relation to expected sample size will be considered when reviewing applications. The Foundation is providing catalytic funding and is not expected to fund the full cost of the surveillance system (clinical and sequencing data collection). The Foundation encourages sites to seek for national or other sources of funding to guarantee the sustainability of their surveillance.

In September 2026, the Executive Committee of the Foundation will select institutions and decide the amount of the grant provided during the season to support the implementation. For sites already participating in the GIHSN, the selection will be conditional to data transfer completion in the previous season.

A formal letter from the Foundation describing grant modalities (in cash contribution) and payment milestones will be sent to the selected sites in October 2026. Kick off meetings or calls with sites to review generic protocol and operational details will be organized in October and November. Sites are expected to implement the year-round surveillance starting November 1st for a one-year duration.

HOW TO APPLY AND HIGHLIGHTS

The Call for proposal is published on the GIHSN website www.gihsn.org

All applications must be submitted on-line on the GIHSN website, using the dedicated application form. Deadline for submission of all applications is July 17^th, 2026 , EOB.

• New sites to the GIHSN: Please create your personal space on-line here on the GIHSN website to proceed. Fulfil your application on-line.
• Recurrent sites (previous year(s) contribution to the GIHSN): Please connect to your personal space on-line here. on the GIHSN website and update your previous application form to account for change, if any, in study implementation and budget.

The following documents should be provided along with the proposal to attest the above status:

• Last annual report of institution applying (administrative document of the institution)
• Financial report (including earnings and balance sheet) of the previous year
• Bank account number (official bank document – with swift number)
• List of the members of the board of governors (i.e., group of people who jointly oversee the activities of the laboratory)
• Copy of the decree of creation (i.e., Statutory act returned by the president of the republic or the head of government)

A GIHSN data sharing agreement (See appendix 2) will be requested to be signed by the selected sites at the start of the season.

Should you have any question, please do not hesitate to reach out to us: contact@gihsn.org