Can the hepatitis A inactivated vaccine cause fever?
Disease description:
I received the inactivated hepatitis A vaccine yesterday, and this morning my head felt slightly warm, as if I might develop a fever. Therefore, I would like to ask whether it is common to experience a fever after receiving the inactivated hepatitis A vaccine.
Doctor's answer (1)
Dr. Yang Ziqi
After receiving the inactivated hepatitis A vaccine, some people may experience fever. This is because, once injected into the body, the inactivated hepatitis A vaccine stimulates the immune system and activates immune cells to fight the virus. During this process, immune cells secrete certain pyrogenic cytokines. These cytokines act on the hypothalamic thermoregulatory center, leading to an increase in body temperature and causing fever. Such reactions are generally considered normal vaccine responses. Typically, the fever is mild and short-lived, resolving on its own within a few days, and usually does not require excessive concern. However, if the fever is severe or persists for an extended period, prompt medical attention is recommended so that doctors can provide targeted treatment based on the individual's specific condition.
