Year 2021
October 2021


Abstract Title
Adult influenza vaccination in Singapore: Who should we target?



Tan Tock Seng Hospital1

Background & Hypothesis

Influenza circulates year-round in tropical Singapore, with excess hospitalization and mortality corresponding to the bi-modal peaks in activity in the middle and end of the year. However, the uptake of influenza vaccination has remained low, in spite of high vaccine availability. We sought to understand the demographic, epidemiological, and clinical factors associated with influenza vaccination uptake among adults.


We included a cohort of 717 adults attending at Tan Tock Seng Hospital’s emergency department for uncomplicated upper respiratory tract infection, from June 2016 to Nov 2018. Histories of influenza vaccination, travel, and prior medical consultation were obtained using a questionnaire survey, and demographic and clinical data extracted from medical records. To assess for independent factors associated with influenza vaccination, multivariable logistic regression models were constructed.


The participants were predominantly male (61%), young (95% aged<=65years), and healthy (68% without co-morbidity). Almost one-in-five (18.4%) received influenza vaccination in the past 12 months, with a significantly higher proportion of highly-educated (diploma and degree holders) (22.6%) than less well-educated (15.5%) having been vaccinated (P=0.016). After adjusting for age>65 and prior medical consultation in the preceding 14 days, females (aOR2.00, 95%CI 1.34-2.97), the highly-educated (aOR1.77, 95%CI 1.16-2.70), those with co-morbidities (aOR2.08, 95%CI 1.36-3.19), ethnic Malays (aOR2.16, 95%CI 1.04-4.51) and recent travellers (aOR1.72, 95%CI 1.04-2.86) were more likely to have received influenza vaccination in the past 12 months.

Discussion & Conclusion

This study provided useful insights into adults to be targeted for seasonal influenza vaccination: the less well-educated, males, non-Malays, and the healthy general population with no plan to travel.