The researchers, whose study appears July 12 in the journal npj Vaccines, evaluated responses to the flu vaccine in 50 adults age 18-45 years and 95 adults age 65 and older, and found that the women in the younger group had a stronger immune response compared to the older women and all men. Experiments in mice yielded similar results, and suggested that estrogen -- levels of which lessen with age in females -- boosts females' immune responses to flu vaccines, while testosterone lowers males' responses. The scientists expect that their results will be generalizable to other vaccines.
"We need to consider tailoring vaccine formulations and dosages based on the sex of the vaccine recipient as well as their age," says study senior author Sabra Klein, PhD, an associate professor in the Department of Molecular Microbiology and Immunology at the Bloomberg School.
Scientists - Women - Responses - Vaccines - Tend
Scientists have known that women tend to have stronger immune responses to vaccines, and also that the elderly tend to have weaker responses. Klein and colleagues in their study set out to get a better understanding of the interaction of these sex- and age-related differences.
First, they evaluated immune responses to the 2009 H1N1 influenza vaccine in 145 human volunteers -- one group age 18-45 years, the other 65 and older. Analyzing key markers of the immune response, the researchers found that, on average, women in the younger group had a stronger response compared to both the men and the older women. The younger women had, for example, a jump in their levels of the important immune protein IL-6 that was almost three times greater than that seen in the younger men, and almost double that seen in older women. Measures of the anti-flu antibody response also were higher for the younger women compared to the men and the older women, though...
Wake Up To Breaking News!