So far, reactions reported after getting a booster shot are similar to those after the two-dose or single-dose primary shots. Fever, headache, fatigue, and pain at the injection site were the most commonly reported side effects, and overall, most side effects were mild to moderate. These side effects are normal signs that the body is building protection and should go away within a few days.
However, as with the two-dose or single-dose primary shots, serious side effects are rare but can occur. After vaccination, be sure to register for V-safe, the after-vaccination health checker. Learn more about the safety monitoring of COVID-19 booster doses.