Whether a baby with a 3mm ventricular septal defect can be vaccinated with the new crown vaccine depends on the baby’s condition. If the baby does not have any discomfort, the baby can be vaccinated with the new crown vaccine; if he/she has symptoms such as dyspnea, heart failure, etc., he/she cannot be vaccinated with the new crown vaccine. If the baby has symptoms such as respiratory distress or heart failure, he/she cannot receive the vaccine. 1. Babies with ventricular septal defects can be vaccinated normally if there are no obvious symptoms, no heart failure, no dyspnea, and they are not in an exacerbation phase of the disease. The New Crown vaccine will not induce a flare-up of the disease, let alone aggravate it. 2. If the baby has a ventricular septal defect with obvious symptoms, such as dyspnea, heart failure, and is in an exacerbation of the disease and needs to be hospitalized, then it is not advisable to receive the new crown vaccine. This is because some people may have adverse reactions to the New Crown Vaccination, which may aggravate the baby’s discomfort. Specific consultation with the vaccinating doctor should be made for evaluation.