What changes in immunity with age and how it affects health

A team led by Prof. Reinhold Ferster from the Hannover Medical School in Germany has conducted an in-depth analysis of immune cells in the blood. The study was the most accurate and detailed of any previously conducted. The team involved not only immunologists, but also specialists in dermatology, virology, as well as pediatrics and allergology.

Thanks to the use of 60 markers for analyzing cells at once, the scientists were able to “see” even subtle changes that had previously gone unnoticed. For example, they divided T-helper cells (CD4+ cells) into 18 different subgroups – so precise classification did not exist until now.

One of the most interesting findings was how much the immune system is affected by chronic disease, obesity, smoking and even a person’s gender. In addition, it was discovered: carriers of dormant cytomegalovirus (a common infection that may not manifest itself in any way) have an increased number of certain memory immune cells in their blood. This may explain why the immune response becomes less effective with age.

To avoid human error, cell typing was not done manually, but with the help of algorithms. The computer model allowed the 97 types of innate and acquired immune cells to be clearly categorized into clusters and revealed patterns that would have been impossible to notice in the usual way.

This approach made it possible to see not only general differences between the young and the elderly, but also to identify unique features within the over-60 age group. For example, changes in the immune system were found to be very different between men and women.

The authors emphasize: immunity is a very complex system, and it differs greatly from person to person. Despite this, the new work brings us closer to understanding why we become more vulnerable to infections as we age and how this can be combated.

These findings are already paving the way for more effective vaccinations and methods of preventing disease in the elderly. And perhaps, in the future, help each of us age with a strong immune system.