I've had very mild effects, including a slight sore arm after some vaccines, even vaccines other than for Covid have given a sore arm sometimes. People have different reactions for different reasons, that is to be expected. I will get another booster in the future if recommended, and am thankful these vaccines are available. Too many people put into their graves from this deadly worldwide pandemic, and I'm glad I'm not one of them.I've had Moderna every time - x 4 - and had no side effects - not even a sore arm!