It's no secret that as we get older our immune system doesn't work as well. We become more susceptible to illness and disease, and less responsive to vaccination.
Researchers at the Stanford University School of Medicine have now discovered that this is due to a specific protein, DUSP6, that accumulates in our immune cells as we age and interferes with our immune system's ability to respond to the presence of foreign bodies, such as a disease pathogen or the components of a vaccine that help our bodies to develop resistance to a disease.
"While 90 percent of young adults respond to most vaccines, after age 60 that response rate is down to around 40-45 percent. With some vaccines, it's as low as 20 percent." says Dr. Jorg Goronzy, senior author of the study, according to Science Daily.
[ Related: Marijuana compound may stop deadly cancer metastasis ]
They also discovered that the micoRNA molecule 'miRNA-181a' directly interferes with the production of DUSP6. The amount of miRNA-181 in our 'naive' immune cells — those that have yet to encounter a foreign body and thus become activated against it — steadily declines with age, and reaches its lowest levels between the ages of 65-70. The researchers stimulated the production of miRNA-181 in the 'naive' immune cells, causing an immediate and drastic reduction in the amount of DUSP6 in them and making them much more responsive to the influenza vaccine.
"We are still far from application in the clinic," said Goronzy. "We need to keep tweaking the compound and testing it in mice to make absolutely sure it's safe enough to try in humans. But improving vaccine responses to overcome age-related immune defects represents a unique opportunity to attain healthy aging."