To compare the safety and clinical efficacy (death, overall hospitalization, hospitalization for influenza or pneumonia) of ID QIV delivered via an intradermal device with imiquimod cream pretreatment with conventional intramuscular (IM) standard dose QIV and IM high-dose TIV
This is a prospective; double-blind randomized controlled study performed in the HKWC. Recruited subjects include subjects ≥50 years and adult subjects ≥18 years with chronic illness. Eligible subjects will be randomly allocated (3:3:2) into one of the three groups in the first year. Group IQ: topical 5% 250mg imiquimod ointment followed by intradermal QIV, Group IM: topical aqueous-cream followed by IM QIV and Group HD: topical aqueous-cream followed by intramuscular high-dose TIV. Hemagglutination inhibition and neutralization antibody titres will be assayed. We plan to recruit 4000 subjects, 1500 subjects in each of the IQ and IM group (500 subjects in each subgroup with 3 subgroups) and 1000 subjects for the HD group (500 subjects in each subgroup with 2 subgroups). In the following year, the IQ and IM groups will be further randomized equally into three subgroups: IQ1, IQ2 and IQ3; IM1, IM2 and IM3; and two subgroups for HD group: HD1 and HD2. Subjects randomized to IQ1, IM1 will receive the QIV with the same topical treatment, delivery mode and vaccine as the first year and HD1 will receive the TIV with the same topical treatment, delivery mode and vaccine as the first year. Subgroup IQ2 and IM2 will be vaccinated as follow: IQ2 will receive topical aqueous-cream followed by IM QIV, IM2 will receive topical imiquimod ointment followed by ID QIV. Subgroup IQ3, IM3, HD2 will receive normal saline as the vaccine for that year, but delivered by the same mode and topical treatment. In the third year, subgroups IQ1, IQ2, IM1, IM2 and HD1 will receive the same topical treatment, delivery mode and vaccine as the second year. Subgroup IQ3, IM3 and HD2 will receive the same topical treatment, delivery mode and vaccine as the first year.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
4,000
quadrivalent influenza vaccine
high-dose trivalent influenza vaccine
imiquimod cream
University of Hong Kong, Queen Mary Hospital
Hong Kong, Hong Kong
RECRUITINGMortality
death rate
Time frame: 3 years
Overall hospitalisation
hospitalisation rate for all diagnosis
Time frame: 3 years
Hospitalisation for influenza
hospitalisation rate with microbiological confirmation of influenza
Time frame: 3 years
Hospitalisation for pneumonia
hospitalisation rate with a clinical diagnosis of pneumonia
Time frame: 3 years
immediate adverse events
immediate adverse events
Time frame: 5 minutes post vaccination
adverse events
Local: redness, swelling, induration, pain and ecchymosis. Redness, swelling, and induration will be graded based on size: Grade 1, under 20mm; Grade 2, 20-50mm. Pain will be graded as follows: Grade 1, pain on touch, Grade 2, pain when arm is moved Systemic: fever, headache, malaise, myalgia, arthralgia and severe adverse events.
Time frame: 7 days post vaccination
immunogenicity
GMT, seroconversion rate, seroprotection rate and GMT fold increase by HI and MN assays on day, 21, 6 months and 1 year
Time frame: at 21 days, 6 months and 1 year after each vaccination
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inactive aqueous cream