Vaccinations should be given on time as much as possible, but if you have to postpone them, you should try to keep the postponement time as short as possible, and generally do not postpone vaccinations for more than a month. It is best to vaccinate when the child is completely healthy. If there is fever, diarrhea or obvious eczema, it is better not to vaccinate in this case because the potential risk is higher. If a small child has not been well, do not consider the timing. Regardless of how much time has passed since the vaccination, vaccination is generally not allowed until the child has been well. Children have to receive many vaccines, and if the previous vaccines are postponed for too long, resulting in a messy schedule for the later vaccinations, the entire vaccination schedule will be disrupted, and it is necessary to make all the readjustments at this time.