Can a common vaccine help the immune system fight cancer?

This study is testing if giving a low-dose cancer drug (lenalidomide) along with a standard pneumonia vaccine can help the body's immune system better recognize and attack early-stage chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). It enrolled 49 adults with early, high-risk forms of these cancers who had no symptoms and did not yet need standard treatment. The main goal is to see if this combination improves the body's antibody response to the vaccine, which might indicate a stronger immune attack on the cancer cells.