People with a body mass index (BMI) ≥30 kg per m2 are strongly recommended to receive annual influenza vaccine.

This is because of the increased risk of severe outcomes from influenza in these people, whether or not they have underlying comorbidities.16 Studies assessing the association of obesity and severe outcomes after infection with the 2009 pandemic influenza strain (A(H1N1)pdm09) showed that people with higher BMI had the highest risk.17-21 People with a BMI of ≥40 kg per m2 (class III obesity) have a particularly high risk of severe influenza.16

Page history

Last updated: 
7 June 2018
Last reviewed: 
7 June 2018