This is true. My immunologist tested my immune system by having me get a pneumonia vaccine. Tested me after about 2 months later and found NO antibodies from the vaccine.
I’m sorry to learn about your immuno-suppressed state. Good to know you work with your immunologist to know whether a vaccine has established its intended benefit. As a result, you can take additional precautions to reduce risk with contagious illnesses. Keep the faith.