How long after receiving the MMR vaccine does fever typically occur?

　　Fever, also known as pyrexia, may occur generally between 6 to 14 days after receiving the MMR (measles, mumps, and rubella) vaccine. If any abnormalities occur, it is recommended to seek medical attention promptly. Detailed analysis is as follows:

　　Some children may experience a stronger immune system reaction after vaccination, and fever may last longer, usually occurring 10 to 14 days after vaccination. In these cases, the immune response triggered by the vaccine components lasts longer, fever appears later, and generally resolves on its own within 1 to 2 days.

　　Most children experience a mild immune system reaction after vaccination, with a brief episode of fever typically occurring 6 to 8 days after vaccination. The immune response begins relatively quickly, causing a slight increase in body temperature, which usually returns to normal within a few hours to 1 day, without other significant discomfort.

　　After receiving the MMR vaccine, it is important to monitor the child's temperature. If the fever exceeds 38.5°C or lasts more than 3 days, prompt medical attention is advised.