Pediatric patient presented to Covid vaccination clinic for scheduled second dose of Pfizer. Inadvertently patient received 0.3ml of Janssen vaccine instead of 0.3 ml of Pfizer vaccine. Patient has had fever, headache, nausea, vomiting, muscles aches, fatigue and diarrhea off and on since vaccination. On 6/24/21 at 12:30AM went to ER due to headache, vomiting, diarrhea and weakness. Diagnosed with a bacterial infection in his stool. Given medicine for pain and vomiting. Per mom, all tests done including for concerns with blood, heart and brain were all normal.