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

> **NCT02957890** · PHASE4 · ACTIVE_NOT_RECRUITING · sponsor: **The University of Hong Kong** · enrollment: 400 (estimated)

## Conditions studied

- Influenza, Human

## Interventions

- **BIOLOGICAL:** Inactivated influenza vaccine (NH formulation)
- **BIOLOGICAL:** Inactivated influenza vaccine (SH formulation)
- **BIOLOGICAL:** Placebo

## Key facts

- **NCT ID:** NCT02957890
- **Lead sponsor:** The University of Hong Kong
- **Sponsor class:** OTHER
- **Phase:** PHASE4
- **Study type:** INTERVENTIONAL
- **Status:** ACTIVE_NOT_RECRUITING
- **Start date:** 2016-11-18
- **Primary completion:** 2025-09
- **Final completion:** 2026-09
- **Target enrollment:** 400 (ESTIMATED)
- **Last updated:** 2023-12-11

## Collaborators

- [object Object]
- [object Object]

## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT02957890

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT02957890, "Immunogenicity of Twice-annual Influenza Vaccination in Older Adults in Hong Kong". Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/clinical/NCT02957890. Licensed CC0.

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