High testosterone levels have been found to activate a group of genes that suppress immune response in men to bacterial, viral, fungal, and parasitic infection by Dr. Mark Davis, professor of microbiology and immunology at Stanford University, and colleagues according to their report in the Dec. 23, 2013, edition of the journal Proceedings of the National Academy of Sciences.
Physicians and scientists have known that men and women differ in their response to vaccination for bacterial, viral, and fungal diseases. Women’s body cells replicate vaccine antibodies faster than men and produce higher levels of antigens against diseases they are vaccinated for. Men have a lower inflammatory response to pathogens than women do. This fact accounts for the higher death rates in women due to the consequences of inflammation.
The researchers found the reason for the difference in immune response between men and women was related to the levels of testosterone circulating in men’s blood. The testosterone does not directly produce the difference. Testosterone acts to reduce the response of a set of genes that produce the immune response to vaccinations.
Women have a low amount of testosterone that can be in their blood but the level is not high enough to produce any interference with the genes that produce the immune response. Men with low levels of testosterone exhibited a greater ability to manufacture antibodies against diseases.
The discovery was made by analyzing the blood of 53 women and 34 men that received an annual influenza vaccination.
The researchers note that older men that are prone to be more susceptible to flu and other transmissible diseases might reconsider the use of testosterone replacement therapy at least during peak flu seasons.