Upper medicine treats the untreated diseases and recommends vaccines for disease prevention on a routine basis. But medicine is only as good as its ingredients. How to choose vaccines for diseases with disrupted immune mechanisms, such as lupus and ITP? This article provides a general introduction to the science. It is a medicine with three toxins According to data provided by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA), there were 20 patients with ITP after the Pfizer COVID-19 vaccine injection, 17 of whom had no thrombocytopenia before vaccination [1]. These 20 patients developed from 1 to 23 days (median 5 days) after vaccination and presented with petechiae or mucosal bleeding (gingival, vaginal, nasal bleeding), with most platelets below 10×10^9/L (1-36×109/L; median 2×109/L) at the time of onset. The advantages outweigh the disadvantages Although some Japanese studies have concluded that inactivated vaccination does not increase the incidence of ITP, it accounts for approximately 1% of ITP incidence after vaccination. According to a French multicenter study published in the journal Blood and recommended by the American Society of Hematology, receiving COVID-19 vaccine has the potential to reduce platelets, but the benefit outweighs the risk, even if the reduction in platelets is manageable with treatment. The conclusion that the benefits of vaccination outweigh the risks also applies to other autoimmune disease populations and other vaccines, such as SLE. Medication and vaccines Hormones can reduce the effectiveness of vaccines. However, inactivated or attenuated vaccines are effective in children at doses of prednisone less than 1 mg/kg per day or less than 40 mg/day. Vaccines are ineffective in children with ≥2 mg/kg or more than 10 kg and who have been on the drug for more than 2 weeks. Try not to use live vaccines while on hormones unless there is no severe immunodeficiency, in young children with hormones for <14 days, <20 mg prednisone per day or equivalent or <2 mg/kg body weight per day, short-acting hormones applied in small doses every other day for a long time, or to maintain physiological doses (replacement therapy), or topical application of hormones. Patients applying CD20 monoclonal antibodies, TNF-α inhibitors, methotrexate, etc., try to recover immunity before using vaccines with good results, otherwise they are ineffective. Even after 1 year of CD20 monoclonal antibody application, the effect of vaccine is not fully recovered. Ibrutinib, etc. may also reduce the effect of vaccine, but specific data studies are still scarce.