You can take fever-reducing medicine if you have a fever after vaccination. Fever and other symptoms after vaccination are normal reactions, which usually last 1-2 days and can be cured by themselves. You can also use physical methods to cool down the temperature, drink more warm water, and use antipyretic drugs if necessary. After vaccination, symptoms such as redness, swelling, heat and pain at the injection site may also occur, which are mostly caused by drug malabsorption. If the adverse reaction is more serious, you can seek medical help.