PurpaPRO

The influenza vaccine may be less effective in the elderly because their B cells are less capable of producing antibodies that can adapt to protect against new viral strains, researchers report. With age, B cells and the antibodies they secrete acquire fewer mutations that would provide flexible protection against the ever-changing flu virus.

A hormone called irisin — produced during exercise — may protect neurons against Alzheimer’s disease.

A new study documents how the quality of a person’s romantic relationship and the life stress he or she experiences at two key points in early adulthood (at age 23 and 32) are related to sleep quality and quantity in middle adulthood (at age 37).