Like any vaccine, COVID-19 vaccines can cause mild side effects. Most reactions to vaccines are mild and go away within a few days on their own.
Reported side effects include fever, fatigue, headache, muscle pain, chills, diarrhoea, and pain at the injection site. The chances of any of these side effects following vaccination differ according to the specific COVID-19 vaccine.
More serious side effects to vaccines that can have long lasting consequence are possible but extremely rare. Vaccines are continually monitored to detect rare adverse events.