Vaccinations against Covid-19 were first made available to high risk people. These included medical workers who came into close contact with people with an active infection. Also included in the high risk category have been older people, with the risk being highest for the oldest and going down from there. What makes older people more likely to contract severe disease than younger people? What makes them more likely to die of an infection?
The answer to those questions depends on the way the human immune system mounts a defense against a viral or bacterial infection. One of our primary defenses against infection is a group of immune cells manufactured in the bone marrow called B-lymphocytes. These B-cells do not last long in the body, and must constantly be replenished from the bone marrow. While active, they are on guard, seeking out and destroying anything they recognize as “foreign,” including viruses and bacteria. In the process of recognizing an invading cell, the B-lymphocyte is transformed into a long-lived memory cell. This cell “remembers” the invader it has encountered. If the body is ever attacked again by the same enemy, it sounds the alarm and raises a defense.
As a person gets older, more and more of her B-lymphocytes are transformed into memory cells, leaving less room for naïve B-lymphocytes to enter the circulation. After a lifetime of successfully fighting disease, a person has lots of memory cells and not so many B-lymphocytes. This is unfortunate, since it is the B-lymphocytes that detect and do battle with pathogens that the person has not encountered before. As the number of memory cells increases, each targeted at some threat that has been seen before, a feedback loop suppresses the production of more naïve B-lymphocytes. Thus the very cells that should be protecting you from novel threats, are not there for you when you encounter a novel threat, such as Covid-19.
What can be done? Is there a way to stop the suppression of the production of B-lymphocytes in older people, so that they can resume producing B-lymphocytes that will protect them from new threats, including both Covid-19, as well as whatever the next pandemic organism turns out to be?
A paper out of Doron Melamed’s lab in Israel titled “Peripheral B-cells repress B-cell regeneration in aging through the TNFα/IGFBP-1/IGF1 immune-endocrine axis” describes this research. If the production of B-lymphocytes in older people can be restarted in those people, who have already faced many different pathogens over the course of a long life, humanity will be in much better shape to handle the next pandemic, when it arrives, as it surely will.
BIO:
Allen G. Taylor is a 40-year veteran of the computer industry and the author of over 40 books, including Develop Microsoft HoloLens Apps Now, Get Fit with Apple Watch, Cruise for Free, SQL For Dummies, 9th Edition, Crystal Reports 2008 For Dummies, Database Development For Dummies, Access Power Programming with VBA, and SQL All-In-One For Dummies, Third Edition. He lectures internationally on astronomy, databases, innovation, and entrepreneurship. He also teaches database development and Crystal Reports through a leading online education provider. For the latest news on Allen’s activities, check out his blog at wwwallengtaylor.com or contact him at allen.taylor@ieee.org.