There is no clear rule on how long you can breastfeed after the New Crown vaccine. According to the past information, breastfeeding is usually not affected after maternal vaccination, but you should observe if there are any uncomfortable symptoms after vaccination, and breastfeed if there is no obvious adverse reaction. In addition, during breastfeeding, the baby’s condition should be observed at the right time for any abnormalities. If the baby has any adverse reactions such as crying, fever, drowsiness or general allergy during breastfeeding, breastfeeding should be suspended in time, and those with serious symptoms should seek medical treatment immediately. Maternal vaccination usually does not affect the quality of breast milk, but if the mother has adverse reactions after vaccination, such as dizziness, fever and other systemic reactions, or allergic reactions such as rash and itching, due to her personal constitution. At this time, the hormone level in the mother’s body will also be affected, which may affect the quality of breast milk and be detrimental to the health of the baby. Therefore, it is recommended to suspend breastfeeding for such people and wait for the symptoms to improve and the body to recover before breastfeeding. Currently, Phase III clinical trials have been completed for the new crown vaccine in China, and breastfeeding is generally safe. If the infant has an abnormal adverse reaction during breastfeeding, he/she should consult a doctor for help.