This clinical trial is focused on studying the body’s immune response to the pneumococcal vaccine. Pneumococcal disease is caused by bacteria that can lead to serious infections like pneumonia, meningitis, and bloodstream infections. The study involves two vaccines: Apexxnar, a 20-valent pneumococcal polysaccharide conjugate vaccine, and Prevenar 13, a 13-valent pneumococcal polysaccharide conjugate vaccine. Both vaccines are designed to protect against different strains of the bacteria that cause pneumococcal disease.
The purpose of the study is to understand how the immune system, particularly the lymph nodes, responds to these vaccines. Lymph nodes are small glands that play a crucial role in the body’s defense against infections. The study will look at the timing of the peak response of certain immune cells, known as B cells, in the lymph nodes after vaccination. It will also examine other immune cells, such as T cells, and various markers that indicate how the immune system is reacting.
Participants in the study will receive one of the vaccines and will have samples taken from their lymph nodes and blood at different times. These samples will help researchers understand the changes in immune cells and the levels of cytokines, which are substances that help regulate the immune response. The study aims to provide insights into how well the vaccines work in stimulating the immune system to protect against pneumococcal disease.



The Netherlands