Leukemia was detected not long after the vaccination is generally considered to have been leukemia before vaccination. Vaccine belongs to the human body immunization preventive biological products, mainly for the prevention and control of the occurrence and prevalence of infectious diseases. After vaccination, a barrier can be established between the human body and the pathogen, which can block the spread of infectious diseases and maintain public health and safety. General vaccination will not cause the occurrence of leukemia, if the vaccination did not take long to check out leukemia, it means that before the vaccination leukemia already existed, may not be obvious symptoms, did not find in time. If you have fever, anemia, skin ecchymosis and other symptoms of leukemia before vaccination, you should go to the hospital for examination in time, and should not be vaccinated.