the missus was mildly under the weather the day after her booster, like a mild flu/cold, but nothing near what she experienced after her second shot (she was useless for 24 hours after shot #2). she did get a two-golf-ball-sized red welt size at the injection site, first time that's happened. BiL & SiL were apparently wrecked the next day and spent it on the couch, both called in sick that day. haven't gotten mine yet, will schedule for next week.