Immunogenicity of Twice-annual Influenza Vaccination in Older Adults in Hong Kong

NCT02957890 | Active Not Recruiting Phase 4 DMC

• 1 other identifier: YHT004.5
• Study Type: interventional
• Target: 400
• Locations: 1 country
• Sites: 1

Brief Summary

This study evaluates the immunogenicity of adding inactivated influenza vaccine with southern hemisphere (SH) formulation to standard once-annual influenza vaccination with northern hemisphere (NH) formulation in older adults in Hong Kong over 9 years. Half of participants will receive twice-annual influenza vaccination with NH and SH formulation, while the other half will receive once-annual influenza vaccination with NH formulation and a placebo.

Conditions

Influenza, Human

Outcome Measures

Primary Outcomes (1)

• Difference in antibody titres

  The difference in antibody titres of participants measured by haemagglutination-inhibition (HAI) assay, evaluated by (1) the proportion of participants who achieve a target rise in antibody titre against each of the vaccine strains at 30 days, and (2) the geometric mean titre (GMT) ratios between the two groups against each of the vaccine strains at 30 days and 182 days. (The targeted rise in antibody titre is defined as the percentage of subjects with either a pre-vaccination HAI titre \<10 and a post-vaccination HAI titre ≥40, or a pre-vaccination HAI titre ≥10 and a minimum four-fold rise in post-vaccination HAI antibody titre.)

  30 and 182 days after each vaccination

Secondary Outcomes (4)

• Seroprotection

  30 days after each vaccination

• CMI responses

  7 days after each vaccination

• Adverse events

  30 days after each vaccination

• PCR confirmed infection

  182 days after each vaccination

Study Arms (2)

Twice-annual influenza vaccination

EXPERIMENTAL

Twice-annual influenza vaccination: administrations of inactivated influenza vaccine (Northern hemisphere formulation, NH) prior to the northern hemisphere winter, plus inactivated influenza vaccine (Southern hemisphere formulation, SH) prior to the northern hemisphere summer.

Biological: Inactivated influenza vaccine (NH formulation); Biological: Inactivated influenza vaccine (SH formulation)

Once-annual influenza vaccination

PLACEBO COMPARATOR

Administrations of inactivated influenza vaccine (Northern hemisphere formulation, NH) prior to the northern hemisphere winter, plus placebo prior to the northern hemisphere summer.

Biological: Inactivated influenza vaccine (NH formulation); Biological: Placebo

Interventions

Inactivated influenza vaccine (NH formulation) BIOLOGICAL

Round 1 (November): 0.5mL FluQuadri®, Sanofi Pasteur, containing 60μg antigen - 15μg for each influenza strain included - with strains recommended by the WHO for the northern hemisphere formulation

Once-annual influenza vaccination; Twice-annual influenza vaccination

Inactivated influenza vaccine (SH formulation) BIOLOGICAL

Round 2 (May): 0.5mL Vaxigrip®, Sanofi Pasteur, containing 45μg antigen - 15μg for each influenza strain included - with strains recommended by the WHO for the southern hemisphere formulation

Twice-annual influenza vaccination

Placebo BIOLOGICAL

Round 2 (May): 0.5mL normal saline

Once-annual influenza vaccination

Eligibility Criteria

• Age: 70 Years - 79 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Adult aged 70-79 years attending GOPCs, DECCs or day care centres for receiving influenza vaccination or medical or preventive care visits.

You may not qualify if:

• Individuals who show signs of dementia (either confirmed by medical records or do not pass the Mini-cog test) or significant cognitive impairment and are not competent to give their consent.
• Individuals who report medical conditions not suitable to receive inactivated influenza vaccines, such as:
• Severe allergic reaction (e.g., anaphylaxis) after previous dose of any influenza vaccine; or to a vaccine component, including egg protein;
• Moderate or severe acute illness with or without fever after any previous influenza vaccination; or
• A history of Guillain-Barré syndrome (GBS) within 6 weeks of previous influenza vaccination.
• Individuals, according to medical record, who report medical conditions not suitable to receive intramuscular injection, such as:
• bleeding disorders
• habitually taking anticoagulants (with the exception of antiplatelets such as aspirin).
• Individuals who have any medical conditions not suitable to receive inactivated influenza vaccines as determined by a clinician.

Sponsors & Collaborators

• The University of Hong Kong: lead
• Centers for Disease Control and Prevention: collaborator
• Hospital Authority, Hong Kong: collaborator

Study Sites (1)

The University of Hong Kong

Hong Kong, China

Location

MeSH Terms

Conditions

Influenza, Human

Condition Hierarchy (Ancestors)

Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases

Study Officials

• Benjamin COWLING, PhD

  The University of Hong Kong

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: October 31, 2016
• First Posted: November 8, 2016
• Study Start: November 18, 2016
• Primary Completion: September 1, 2025
• Study Completion (Estimated): September 1, 2026
• Last Updated: December 11, 2023

Record last verified: 2023-12

Data Sharing

• IPD Sharing: Will share

Locations

CN (1)