New study reveals hidden immune protection from COVID-19 mRNA vaccines

Researchers at Columbia University Vagelos College of Physicians and Surgeons have uncovered how COVID-19 mRNA vaccines bolster the immune system by generating memory T and B cells, critical for long-term immunity. These cells accumulate in tissues like the lungs, spleen, and bone marrow, offering protection even when evidence of immune memory is not detectable in the blood. The study, led by Dr. Donna Farber, professor of microbiology and immunology, highlights an intriguing possibility: individuals who show no signs of vaccine-induced immunity in blood tests may still possess robust immune defenses stored in lymphoid tissues and infection-prone areas. Hidden immunity beyond the bloodstream “Many people, especially seniors, who seem to lack immunological memory in their blood may actually have more protection than we realize,” says Dr. Farber. While blood-based memory cells and antibodies tend to decline after vaccination, particularly in older individuals, this research suggests that critical memory cells are retained within tissues, offering...