Assessment of Viral Shedding in Children Previously in Receipt of Multiple Doses of Live Attenuated Influenza Vaccine (LAIV) Compared to Influenza Vaccine-naïve Controls (Flushed)
Influenza Vaccination, Influenza, Vaccination
About this trial
This is an interventional prevention trial for Influenza Vaccination
Eligibility Criteria
Inclusion Criteria:
-
Children may only be included in the study if all the inclusion criteria are met:
Children age 6 to 13 years of age on enrolment and with either:
- Prior LAIV vaccination in at least 2 out of the 3 previous years
- Have never received LAIV or IIV in previous years
- Children eligible to receive LAIV in accordance with Green Book advice [https://www.gov.uk/government/organisations/public-health-england/series/immunisation-against-infectious-disease-the-green-book]
- Written informed consent given by parent/ guardian and assent from child (both must be in place to proceed)
Exclusion Criteria:
-
Children may not be included in the study if any of the following apply:
- Admission to Paediatric ntensice care unit (PICU) for invasive ventilation due to a respiratory illness in the preceding 2 years.
Contraindications to LAIV (notwithstanding allergy to egg protein), which include:
- Hypersensitivity to the active ingredients, gelatin or gentamicin (a possible trace residue)
- Previous systemic allergic reaction to LAIV
- Previous allergic reaction to an influenza vaccine (not LAIV) is a relative contra-indication, which must be discussed with the CI to confirm patient suitability
Children/adolescents who are clinically immunodeficient due to conditions or immunosuppressive therapy such as: acute and chronic leukaemias; lymphoma; symptomatic HIV infection; cellular immune deficiencies; and high-dose corticosteroids*.
*High-dose steroids is defined as a treatment course for at least one month, equivalent to a dose greater than 20mg prednisolone per day (any age), or for children under 20kg, a dose greater than 1mg/kg/day.
NB: LAIV is not contraindicated for use in individuals with asymptomatic HIV infection; or individuals who are receiving topical/inhaled/low-dose oral systemic corticosteroids or those receiving corticosteroids as replacement therapy, e.g. for adrenal insufficiency.
- Children / adolescents younger than 18 years of age receiving salicylate therapy because of the association of Reye's syndrome with salicylates and wild-type influenza infection.
- Pregnancy
Contraindications to vaccination on that occasion, e.g. due to child being acutely unwell:
- Febrile ≥38.0oC in last 72 hours
- **Acute wheeze in last 72 hours requiring treatment beyond that normally prescribed for regular use by the child's treating healthcare professional
- **Recent admission to hospital in last 2 weeks for acute asthma
- **Current oral steroid for asthma exacerbation or course completed within last 2 weeks
Any other significant condition or circumstance which, in the opinion of the investigator, may either put the participant at risk because of participation in the study, or may influence the result of the study, or the participant's ability to participate in the study.
- Items 3b-3d are relative contra-indications: Many children with "difficult-to-control" symptoms fail to meet these criteria on a routine basis. Where these are present, the CI is able to authorise participation on a case-by-case basis, after assessing the child at the time of enrolment.
Administration of another live vaccine (e.g. MMR) within the previous 4 weeks is no longer a contra-indication to LAIV administration, according to updated UK Department of Health guidelines.
NB: See Summary of Product Characteristics for full details of contra-indications to LAIV.
Sites / Locations
- Gloucestershire primary care
- Hertfordshire primary care
- Imperial Healthcare NHS Trust
Arms of the Study
Arm 1
Arm 2
Experimental
Experimental
naive
prior vaccinees
Children who have never received any influenza vaccine (The two groups are defined by immunisation history, all receive the same intervention in the study)
Children who have received at least two doses of Fluenz Tetra previously (The two groups are defined by immunisation history, all receive the same intervention in the study)