INFLUENZA VIRUS B/AUSTRIA/1359417/2021 - LIKE STRAIN; INFLUENZA VIRUS A/VICTORIA/4897/2022 (H1N1)PDM09 - LIKE STRAIN; INFLUENZA VIRUS A/THAILAND/8/2022 (H3N2)-LIKE STRAIN for Influenza

Inclusion criteria

• {"criterion_text":"- Age between two and seven years old"}
• {"criterion_text":"- Parents ability and willingness to adhere to protocol-specified procedures, including availability of a freezer at home to store samples. Donating blood is optional as this is a secondary endpoint."}

Exclusion criteria

• {"criterion_text":"- Recipient of any influenza vaccine (both LAIV or IIV) in the same or a previous flu-season."}
• {"criterion_text":"- Recipient of any other vaccine within one month prior to inclusion-date."}
• {"criterion_text":"- Meeting one or more contraindications for the Fluenz vaccine as stated in paragraph 6.3 of the protocol."}
• {"criterion_text":"- Substantial language barrier of either potential subject or parent. Participants and their parents are asked to self-collect samples during this trial, therefore instructions need be given and adequately understood."}

Primary endpoints

• {"endpoint_text":"- Presence or absence of viral shedding of vaccine-strains after first and second dose of LAIV in nasal lining fluid, collected using nasosorptions and analyzed with RT-qPCR.","definition_or_measurement_approach":"Measured in nasal lining fluid collected using nasosorptions and analysed with RT-qPCR to determine presence/absence of vaccine-strain viral shedding after first and second LAIV doses."}

Secondary endpoints

• {"endpoint_text":"- LAIV shedding kinetics (density and duration) during first and second dose of LAIV, measured in nasal lining fluid using nasosorptions and analyzed with RT-qPCR.","definition_or_measurement_approach":"Measured in nasal lining fluid collected using nasosorptions and analysed with RT-qPCR to assess density and duration of LAIV shedding."}
• {"endpoint_text":"- Change in influenza specific mucosal antibodies (including IgA) in nasal lining fluid before and after first and second dose of LAIV. Measured in nasal lining fluid from nasosorptions and analyzed for binding and/or functional capacity.","definition_or_measurement_approach":"Measured in nasosorption-derived nasal lining fluid; assays include binding and/or functional capacity assessments for mucosal IgA and other influenza-specific antibodies."}
• {"endpoint_text":"- Nasal immune responses during LAIV, with soluble proteins measured in nasal lining fluid from nasosorption samples.","definition_or_measurement_approach":"Soluble proteins measured in nasal lining fluid from nasosorption samples to characterise nasal immune responses."}
• {"endpoint_text":"- Nasal colonization and infection dynamics by other URT bacteria and viruses, comparing composition before and after LAIV. Samples will be collected using nasosorptions and analyzed with molecular methods.","definition_or_measurement_approach":"Nasosorption samples analyzed with molecular methods to compare upper respiratory tract bacterial and viral composition before and after LAIV."}
• {"endpoint_text":"- Analysis of peripheral immune system in whole blood collected at baseline and 28 days post LAIV dose 1. Measured using tools such as spectral flow cytometry.","definition_or_measurement_approach":"Whole blood collected at baseline and day 28 post-dose 1; peripheral immune profiling using methods such as spectral flow cytometry."}
• {"endpoint_text":"- Serum and mucosal IgG and IgA post-LAIV, comparing baseline to day 28 post-LAIV. Measured through binding and functional assays.","definition_or_measurement_approach":"Serum and mucosal IgG/IgA measured at baseline and day 28 using binding and functional assays to compare responses."}
• {"endpoint_text":"- Correlating immune responses and shedding kinetics with data from baseline questionnaire and daily questionnaires assessing RTI-related symptoms. Collected using electronic recordings.","definition_or_measurement_approach":"Immune and shedding data correlated with questionnaire data (baseline and daily electronic recordings) assessing respiratory tract infection-related symptoms."}

Methods

• Letter to GP (document: L2_2024-513933-18-00 Letter to GP) — channel: letters to general practitioners in the Netherlands to inform clinicians about the study and invite referrals.
• Posters (documents: K2_recruitment arrangement poster NL and alternative) — channel: recruitment posters aimed at parents of young children in the Netherlands.
• Recruitment arrangements document (K1_recruitment arrangements 2024-513933-18-00) — describes local recruitment arrangements (document listed for the Netherlands).

Netherlands

Earliest CTIS Part Ii Submission Date

24-06-2025

Latest Decision Or Authorization Date

24-07-2025

Processing Time Days

30

Number Of Sites

1

Number Of Participants

20

Primary sponsor

Full Name

Leids Universitair Medisch Centrum (LUMC)

Organisation Type

Hospital/Clinic/Other health care facility

Country Of Registered Address

Netherlands