Here's an informative article on the life cycle of B-cells (B-Lymphocytes), explaining how they become sensitised to a viral infection, work to clear it from your body, then go through a quality control process that makes them more specific to that virus and how that can work against us with viruses that can change their coat like the flu or come in different variants like dengue fever.
Kim Jacobson, Senior Research Fellow at Monash University, Melbourne, Australia explains:
Understanding this article provides you with the background for an excellent appreciation of why CLL makes us immune compromised. With CLL, the vast majority of our B-cells are clonal B-cells and they disrupt the process by which new, healthy B-cells become sensitised to new infections (or antigens from the infecting virus or bacteria in a non-live vaccine), so we don't go on to make the long lived plasma and memory B cells mentioned in the article. That's why vaccines don't work that well for us and why our antibodies/Immunoglobulins (IgA, IgG and IgM) gradually drop away over time and we may need IVIG transfusions to help us stay free of infections.
Photo: Damsel flies feast on mosquito larvae in their larval form and on adult mosquitoes when they are flitting around wetlands, so we should appreciate them both for their beauty and for protecting us from mosquito borne diseases.