Clinical trial NCT06676644: Estimate the Safety and Effectiveness of Adjuvanted Influenza Vaccine Among Asian Elderly People When Compared to Non-adjuvanted Vaccines
Official title: A Comparative Study on the Immunogenicity and Safety of Adjuvanted Versus Non-Adjuvanted Influenza Vaccines in the Elderly
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Influenza Vaccines
Elderly
Keywords: influenza
adjuvanted vaccine
immunogenicity
elderly
safety
Lead sponsor: National Taiwan University Hospital
Sponsor class: OTHER
First posted: 2024-11-06
Enrollment: 200
Sex: ALL
Minimum age (years): 65
Standard ages: OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: To compare the immunogenicity, cellular immune response, and safety between adjuvanted (aIIV4) and non-adjuvanted (IIV4) seasonal influenza vaccines in the Taiwanese elderly population with chronic medical conditions.

Detailed description: Annual influenza vaccination is the most important and cost-effective intervention in reducing the impact of influenza, and a key component of the WHO response and preparedness efforts for influenza of pandemic potential. Reduced effectiveness of conventional egg-based vaccination was observed among risk group, such as elderly and people on with chronic medical conditions, which may result from their impaired immunogenicity. WHO, as well as ACIP of the USA, Europe, and Australia suggested adjuvanted influenza vaccines as one of alternatives for those people, which could decrease the disease burden significantly in several analyses. An adjuvanted commercial vaccine has been approved in Taiwan recently, but the local data of safety and effectiveness analysis is limited. This 1-year randomized control trial is designed to estimate the safety and effectiveness of adjuvanted influenza vaccine among Asian elderly people when compared to non-adjuvanted vaccines.

Eligibility criteria: Inclusion Criteria:

* Adults aged 65 years or above
* Presence of at least 1 chronic medical condition associated with increased risk of complicated influenza, including hypertension, chronic obstructive pulmonary disease (group A, B, E), asthma, congestive heart failure (ACC/AHA stage A, B, C, D), coronary arterial disease, diabetes mellitus, chronic liver disease (Child-Pugh score A, B, C) or chronic kidney disease (stage 1\~4), neuromuscular disorders, hematological or solid organ malignancies, recipient of hematopoietic stem cell transplantation or solid organ transplantation.

Exclusion Criteria:

* Contraindications to influenza vaccination including history of severe adverse event after vaccination, such as anaphylaxis or Guillain-Barré Syndrome, or a severe bleeding tendency
* Prior receipt of influenza vaccination during the current flu season.
* Determination by the Principal Investigator (PI) that the participant is ineligible for enrollment based on clinical assessment.

Primary outcomes:
measure: The seroconversion rate (SCR) measured by the change in hemagglutination inhibition (HI) titer against the vaccine strains in serum between Day 1 (pre-vaccination) and Day 29.
timeFrame: Measured through Day 29
Secondary outcomes:
measure: The geometric mean titer (GMT), seroprotection rate (SPR), cellular immune responses on Day1, Day 29 (±3), Day 181 (±7), and Day 361 (±7)
timeFrame: Measured through Day 361
measure: Incidence of severe adverse reactions within 28 days after immunization.
timeFrame: Measured through Day 28
measure: Incidence of laboratory-confirmed influenza during the study period.
timeFrame: Measured through Day 361
measure: Incidence of emergency department visits and hospitalizations related to respiratory illness, all-cause mortality during the study period.
timeFrame: Measured through Day 361
Other outcomes:
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