Study: Flu Vaccine Less Effective for Men

It's been long known, there are differences in immune system response to infection and vaccination among boys and girls. Women often have a much more robust response.

 But so far scientists have not been able to explain why . A recent study suggests that testosterone levels may affect the efficacy of the flu vaccine .


Vaccines likely to be less effective for men than for women , because of the high levels of testosterone in men , which inhibit the immune response .
A research team led by Mark Davis of Stanford University in California identified a group of genes involved in lipid metabolism and likely to affect the level of testosterone .
The latest research , which was released in the official journal of the Proceedings of the American Academy of Sciences ( PNAS ) , noting how the response of a group of respondents consisted of 34 men and 53 women from different age groups vary, the flu vaccine .
Past studies have found the existence of levels of varying effectiveness and side effects vary for men and women who get the vaccine , for example against influenza , yellow fever , measles and mumps .

Antibody more for women
The researchers in the new study confirms that women react to the flu vaccine by producing more antibodies , and cytokines , which act as peregulasi hormone and plays an important role in the immune system .

The biggest difference was found in the vaccine for the H3N2 flu strain that is aggressive. Researchers explore gender differences in reaction to the second group of genes involved in lipid metabolism are also known to be responsible reduce the immune response.

These genes react more strongly to the hormone testosterone in men.

Scientists speculate that in prehistoric times, men with less aggressive immune response have a better chance to survive, despite playing the role of hunters and warriors who tend to expose them to injury and may lead to infection.

Excessive immune response to infection could prove to be more dangerous than the pathogen itself, obviously the scientists.