Common side effects of the COVID-19 vaccines include injection site pain, fatigue, headache, muscle pain and fever.
Data from the Pfizer/BioNTech and Moderna trials also show the side effects included joint pain and chills. These reactions are more likely after the second dose of those vaccines, given several weeks after the first, and are more common and severe in younger people. The Johnson & Johnson side effects, too, were more common in 18- to 59-year-old participants, and also included nausea.
As the CDC explains, these common side effects are normal signs that your body is beginning to mount an immune response and the symptoms should go away within several days. Some people have no side effects, and that is normal, too.
Rarely, the COVID-19 vaccines may cause more serious problems.
For more information on these rare adverse events, see “How safe are the vaccines?”