Related Experiment Video
Updated: Aug 12, 2026
06:34
An Optimized Hemagglutination Inhibition (HI) Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
Vertical Vaccination Against Infant Influenza Hospitalization in a Tropical Setting
Liang En Wee1,2,3,4,5, Nicole Shu-En Goh5, Reen Wan-Li Ho5
1Communicable Diseases Agency, Singapore.
JAMA Network Open
|August 11, 2026
Summary
Maternal influenza vaccination significantly reduced infant hospitalization risk in tropical Singapore. This strategy offers 41% vaccine effectiveness (VE) against hospitalization for infants under 6 months.
Area of Science:
- Public Health
- Epidemiology
- Immunization
Background:
- Maternal influenza vaccination is proven effective in temperate climates but lacks robust evidence in tropical regions with year-round influenza transmission.
- Infants under 6 months are vulnerable to influenza complications and too young for vaccination.
Purpose of the Study:
- To determine the clinical effectiveness of maternal influenza vaccination in preventing infant influenza hospitalization in a tropical setting.
- To assess the impact of maternal vaccination on infant hospitalization rates in Singapore, a tropical country.
Main Methods:
- A retrospective cohort study analyzed data from Singapore's national administrative databases (May 2017-April 2024).
- Included were infants born between May 2017 and December 2023, linked to maternal vaccination status via the National Immunization Registry.
- Overlap-weighted Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHR) and vaccine effectiveness (VE).
Main Results:
- The study included 221,185 infants; 25.9% were born to vaccinated mothers.
- Infants born to vaccinated mothers had a significantly lower risk of influenza hospitalization (aHR, 0.59; 95% CI, 0.45-0.77).
- Maternal influenza vaccination demonstrated a 41% (95% CI, 23%-55%) vaccine effectiveness against infant hospitalization, regardless of trimester or season.
Conclusions:
- Maternal influenza vaccination during pregnancy is effective in reducing infant influenza hospitalization in tropical regions with year-round transmission.
- This strategy provides significant protection for infants too young to be vaccinated.
- Immunizing mothers at any point during pregnancy is a viable public health approach to protect infants from influenza.
Related Concept Videos
01:51Vaccinations
Overview
01:27Influenza
Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated...
01:18Yellow Fever
Yellow fever is a viral hemorrhagic disease caused by the yellow fever virus (YFV), a member of the Flaviviridae family. It is transmitted primarily by Aedes and Haemagogus mosquitoes in tropical and subtropical regions of Africa and South America. After transmission through a mosquito bite, the virus initially replicates in skin-resident immune cells such as dendritic cells and macrophages. These cells then migrate to the lymph nodes, where viral replication increases, eventually leading to...
01:29Respiratory Syncytial Virus Disease
Human respiratory syncytial virus (RSV) is a widespread pathogen that primarily targets infants and young children but also poses a serious health risk to elderly and immunocompromised individuals. Belonging to the Pneumoviridae family, RSV is a negative-sense, single-stranded RNA virus within the Pneumovirus genus. Its global health burden is significant, with millions of cases annually resulting in hospitalizations and mortality, particularly in resource-limited settings. Although most...
01:24Smallpox
Smallpox is a severe contagious disease caused by the Variola major virus, a double-stranded DNA member of the Poxviridae family.Variola major transmission occurs primarily via inhalation of virus-laden droplets or direct contact with infectious scabs. The incubation period averages approximately seven days, although it may range from 7 to 17 days depending on the inoculum and host factors.Clinically, the prodromal phase is marked by an abrupt onset of high fever, malaise, headache, and myalgia.
01:17Poliomyelitis
Poliomyelitis is caused by poliovirus, a small, non-enveloped, positive-sense RNA virus of the Picornaviridae family and Enterovirus genus. Transmission occurs primarily via the fecal-oral route, often through ingestion of contaminated water or food. The virus initially replicates in the oropharynx and intestinal mucosa, particularly in lymphoid tissues such as the tonsils, Peyer’s patches, and regional lymph nodes. Primary viremia follows, allowing dissemination throughout the body.In most...