Related Experiment Video
Updated: Oct 27, 2025
An Optimized Hemagglutination Inhibition HI Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
Influenza vaccine effectiveness against influenza-associated hospitalization in children in Hong Kong, 2010-2020
Huiying Chua1, Mike Y W Kwan2, Eunice L Y Chan3
1WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
Insights
Annual influenza vaccination effectively protects children against hospitalization. Vaccine effectiveness was higher in younger children and against specific influenza A strains, supporting childhood vaccination programs.
Area of Science:
- Pediatric infectious diseases
- Vaccinology
- Public health
Background:
- Influenza virus infections pose a significant risk, leading to hospitalizations in children.
- Annual influenza vaccination is a key strategy for protecting pediatric populations.
Purpose of the Study:
- To evaluate the effectiveness of influenza vaccines in preventing hospitalizations among children.
- To analyze vaccine effectiveness by age group, influenza type/subtype, and time within seasons.
Main Methods:
- A test-negative design study was conducted from 2010/11 to 2019/20.
- Children hospitalized with acute febrile respiratory illnesses were enrolled, and influenza status was determined via RT-PCR or culture.
- Vaccine effectiveness (VE) was estimated using a conditional logistic regression model.
Main Results:
- Influenza vaccination demonstrated effectiveness in preventing influenza-associated hospitalizations across all pediatric age groups.
- Vaccine effectiveness was greater in younger children compared to older children.
- Effectiveness varied by influenza type, with higher VE observed against influenza A(H1N1)pdm09 compared to A(H3N2) and B.
Conclusions:
- The childhood influenza vaccination program in Hong Kong has successfully reduced influenza-associated hospitalizations, especially in younger children.
- These findings reinforce the importance of influenza vaccines as an effective tool for influenza control and prevention in children.
Background:
Influenza virus infections can cause hospitalizations in children, and annual vaccination of children can provide protection against influenza.
Methods:
We analyzed a test-negative design study with data spanning from 2010/11 through 2019/20 to evaluate influenza vaccine effectiveness (VE) against influenza hospitalization in children by age group, influenza type/subtype and time period within each season. We enrolled children admitted to hospital with acute febrile respiratory illnesses. Nasopharyngeal aspirates were tested by culture and/or RT-PCR to determine influenza status, and vaccination status was obtained by interviewing parents or legal guardians and was verified where possible. VE was estimated by conditional logistic regression model adjusting for sex, age and age-squared, matching on week.
Results:
Influenza seasons in Hong Kong are prolonged with influenza-associated hospitalizations occurring in almost every month of the year during the study period. Influenza vaccination was effective in preventing influenza-associated hospitalizations in children of all ages. Influenza VE was higher in younger children than in older children, and higher against hospitalization due to influenza A(H1N1)pdm09 than A(H3N2) and B.
Conclusions:
The childhood influenza vaccination program in Hong Kong has prevented influenza-associated hospitalizations particularly in younger children. Our findings support the use of influenza vaccines in children as an effective approach to influenza control and prevention.
More Related Videos
12:09Measuring Influenza Neutralizing Antibody Responses to AH3N2 Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells
Published on: November 22, 2017
08:52Use of an Influenza Antigen Microarray to Measure the Breadth of Serum Antibodies Across Virus Subtypes
Published on: July 26, 2019
