This study evaluates immunologic response following COVID-19 vaccination in children, adolescents, and young adults with cancer. Vaccines work by stimulating the bodys immune cells to respond against a specific disease. The immune response produces protection from that disease. Effects from cancer and from treatments for cancer can reduce the bodys natural disease fighting ability (called immunity). Factors such as vaccine type, timing of vaccine dosing related to treatment for cancer and number of vaccine doses or boosts (extra vaccine shots) may strengthen or diminish the bodys protective immune response. This study may help researchers learn more about how the bodys immune system responds to the COVID-19 vaccine when the vaccination is given during or after cancer treatment.

This study aims to use clinical and biological characteristics of acute leukemias to screen for patient eligibility for available pediatric leukemia sub-trials. Testing bone marrow and blood from patients with leukemia that has come back after treatment or is difficult to treat may provide information about the patient's leukemia that is important when deciding how to best treat it, and may help doctors find better ways to diagnose and treat leukemia in children, adolescents, and young adults.