After playing the new crown vaccine red bumps very itchy generally considered with the vaccination of adverse reactions, triggering hives and other reasons. 1. Adverse reactions to vaccination: the vast majority of the population in the new crown vaccine without any adverse reactions, a small number of people in the new crown vaccine vaccination can appear red bumps, itching and other symptoms, most of the 1 ~ 2 days can be naturally subside, without special treatment. 2. triggering hives: if the vaccinated people belong to the allergic body, hives can occur after vaccination with the new crown vaccine, manifested as red bumps with itching and other body parts, if the allergy is severe, it can cause anaphylactic shock. After the new crown vaccination need to stay 30 minutes, if some adverse reactions need to go to the hospital immediately and treatment, you can not randomly use drugs.