December 26, 2013

Testosterone May Undermine Flu Vaccine Effectiveness for Men

Testosterone May Undermine Flu Vaccine Effectiveness for Men

(HealthDay News) – Differences in expression of genes involved in lipid metabolism regulated by testosterone may explain why men have less robust immune responses than women, according to a study published online Dec. 23 in the Proceedings of the National Academy of Sciences.

David Furman, PhD, from the Stanford University School of Medicine in California, and colleagues analyzed the neutralizing antibody response to a trivalent inactivated seasonal influenza vaccine and various immune parameters in 53 women and 34 men of various ages.

The researchers found that women had higher serum expression of inflammatory cytokines and elevated antibody responses to the vaccine regardless of age. A cluster of genes involved in lipid biosynthesis known to be up-regulated by testosterone correlated with the poor antibody response, and men with higher serum testosterone levels and associated gene signatures had the lowest antibody response. The gender-specific differences in immune responses were greatest for the H3N2 influenza strain.

"These results demonstrate a strong association between androgens and genes involved in lipid metabolism, suggesting that these could be important drivers of the differences in immune responses between males and females," Furman and colleagues conclude.