The third dose of the new CRP vaccine does not cause leukemia. At this time, there is no evidence that the new CRP vaccine causes leukemia, and there is no clear causal link between the two. The claim that the new CRP vaccine causes leukemia is most likely due to a “coincidental reaction”. The “coincidental reaction” is not an adverse reaction to the new CAPV, and there is no necessary connection between this reaction and the new CAPV. It mainly refers to the coincidental onset of disease after vaccination when the vaccinated person was in the incubation period or in the early stage of the disease. This creates the illusion that leukemia is induced by the new coronavirus vaccine. On the contrary, patients with malignant tumors are more susceptible to infections than the general population, and the suitability of vaccination for this group of people needs to be evaluated comprehensively according to the recommendations of specialists. Timely vaccination after satisfactory evaluation can provide effective protection.