Nine-valent usually refers to the nine-valent cervical cancer vaccine, nine-valent cervical cancer vaccine arm pain after the third shot may be a common adverse reaction, may also be localized infection. Nine-valent cervical cancer vaccine is a relatively common vaccine to prevent cervical cancer, after the third injection of nine-valent cervical cancer vaccine may appear arm redness, swelling, pain, bleeding and muscle weakness common adverse reactions. Generally there is no adverse effect on the body and it will be relieved on its own. It may also be due to limited inflammation caused by the needle eye that has not completely healed after the vaccination with the vaccine, resulting in hard lumps, swelling and pain in the arm. If the pain is prolonged, it is recommended to go to the hospital to consult a doctor, and if there is an infection, you need to go to a regular hospital in time for treatment. It should be noted that not all people are suitable for vaccination with the nine-valent vaccine, and it is recommended to be vaccinated under the guidance of a doctor.