Recent evidence has shown that obesity is an independent risk factor for influenza-related complications and has also been linked to decreased responses to seasonal flu vaccination.
To explore whether vaccine adjuvants can increase the immunologic response to vaccination in obesity, researchers at St Jude Children’s Research Hospital inoculated lean and obese mice against two different strains of flu using alum-adjuvanted, squalene-adjuvanted and non-adjuvanted vaccines.
They found that adjuvanted vaccinations resulted in increased seroconversion and the production of neutralising and non-neutralising antibodies in all mice. However, obese mice were not protected against flu when they were subjected to viral challenge.
Reporting in mBio (online, 2 August 2016)
, the researchers conclude that the growing prevalence of obesity in the population means there is a critical need to understand why it results in impaired vaccine responses.
 Karlsson EA, Hertz T, Johnson C et al. Obesity outweighs protection conferred by adjuvanted influenza vaccination. MBio 2016;7:e01144-16. doi: 10.1128/mBio.01144-16