FluSNIFF-Toddler
FluSNIFF-Toddler
Sponsored by the University Hospital Southampton NHS Foundation Trust
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A Phase 2 randomised, single blinded, placebo controlled, cross-over trial of a single dose of live attenuated influenza vaccine in 12-23 month old children (FluSNIFF-toddler)
What is this study about?
We are testing the safety of a nasal flu vaccine spray in children aged 12–23 months. The spray (Fluenz) is already approved in children aged 2 years and older and given each winter.
Depending on the results of this study, the NHS may offer it to 1-2 year old children in the future.
Depending on the results of this study, the NHS may offer it to 1-2 year old children in the future.
Your Rights, Data Sharing & Privacy
Any child aged 12 months up to one day before their second birthday and in generally good health.
We will ask about allergies, medicines, and any medical history to make sure your child can safely take part.
We will ask about allergies, medicines, and any medical history to make sure your child can safely take part.
What will happen?
Pre Screening and Consent
Invitation: A brief online questionnaire checks if your child meets the eligibility criteria.
eConsent: If eligible, you’ll review study information, verify your identity, answer short comprehension questions, and give consent by signing electronically.
Support Available: You can pause anytime to speak with a study nurse before completing your consent.
eConsent: If eligible, you’ll review study information, verify your identity, answer short comprehension questions, and give consent by signing electronically.
Support Available: You can pause anytime to speak with a study nurse before completing your consent.
Visit 1 (In GP Clinic, ~30 min)
Re-confirm consent and check health. A computer will randomly choose whether your child gets the flu spray or a spray (placebo) at this visit.
Visit 2 (in GP clinic, 28 days later, ~30 min)
Ask about any symptoms since Visit 1.
Your child gets the other spray (flu vaccine if they had placebo first, or vice versa).
Your child gets the other spray (flu vaccine if they had placebo first, or vice versa).
Follow-up (Day 56, by phone or online)
Ask about any health problems in the 28 days since Visit 2.
Additional Obligations
You’ll be asked to complete a short electronic diary (under 5 minutes) at 7 and 14 days after each visit, to report any urgent or emergency NHS care your child needed. If your child is admitted to hospital before the final visit, please inform the study team by email or phone.
Who runs this study?
Sponsor: University Hospital Southampton NHS Foundation Trust
Research sites: GP practices and hospitals around England
Research facilitator: uMed works on behalf of the Sponsor and Research sites and identifies eligible children, sends invitations to participate, manages consent, collects information from parents, extracts study-related data, and sends it to the research team -- following UK data-protection rules.
Research sites: GP practices and hospitals around England
Research facilitator: uMed works on behalf of the Sponsor and Research sites and identifies eligible children, sends invitations to participate, manages consent, collects information from parents, extracts study-related data, and sends it to the research team -- following UK data-protection rules.
Possible benefits & risks
Benefit: Your child will receive the nasal flu vaccine for free, which will protect against severe flu.
Common mild side-effects: Runny nose, cough, fever usually last 1-2 days.
Rare risks: Allergic reaction (rash, swelling, difficulty breathing). The study team is trained and prepared to treat this unlikely event immediately.
We will watch closely for any wheezing and record any doctor visits for breathing problems.
Common mild side-effects: Runny nose, cough, fever usually last 1-2 days.
Rare risks: Allergic reaction (rash, swelling, difficulty breathing). The study team is trained and prepared to treat this unlikely event immediately.
We will watch closely for any wheezing and record any doctor visits for breathing problems.
Your Rights, Data Sharing & Privacy
Your choice: Taking part is voluntary. You can withdraw at any time - no reason needed - and your usual medical care will not be affected.
If you withdraw: No new data will be collected, but data and samples already gathered may still be used unless you ask us to remove them (where allowed).
Your child’s routine health records (GP notes, NHS Digital data, hospital records) will be shared with uMed on behalf of the study team.
We will keep your child’s data secure and coded so they cannot be identified in any reports.
Anonymous data may be used for future flu research without asking you again.
If you withdraw: No new data will be collected, but data and samples already gathered may still be used unless you ask us to remove them (where allowed).
Your child’s routine health records (GP notes, NHS Digital data, hospital records) will be shared with uMed on behalf of the study team.
We will keep your child’s data secure and coded so they cannot be identified in any reports.
Anonymous data may be used for future flu research without asking you again.
BBC FluSSNIFF
FluSNIFF in the news - BBC: Children under two could get nasal flu vaccine
Read the article
FluSNIFF Season 1
FluSNIFF Toddler Season 1 Update
Season 1 of the FluSNIFF-Toddler study ran from 22 September 2025 to mid-January 2026, during which 1,193 children were successfully randomised. Season 2 is set to open in August 2026, with new GP practice sites joining across England.
Contact Us
Get in touch
If you would like to speak to a nurse about FluSNIFF Toddler, please contact:
