Riddle of why overweight people don't respond to flu vax

Flu shots are less effective for obese adults than their normal-weight peers, say vaccination and infectious diseases experts.

Despite robust serological responses to the vaccination, obese people are twice as likely to develop influenza as their normal weight peers, they found.

The researchers speculate this is due to the T-cells of obese people not functioning properly.

The finding challenges the current standard for correlates of protection, suggesting antibody titres to determine vaccine effectiveness in an obese population may not be of much use.