If you think there was an overdose, call your local poison control center or ER right away. Signs of a very bad reaction to the drug. These include wheezing; chest tightness; fever; itching; bad cough; blue or gray skin color; seizures; or swelling of face, lips, tongue, or throat. Big change in balance. Change in hearing. Feeling very tired or weak. Very nervous and excitable. Very upset stomach or throwing up. Very loose stools (diarrhea), even after drug is stopped. Not able to pass urine. Any rash. Some side effects may happen up to 2 weeks after the shot. Report them to your doctor. Side effect or health problem is not better or you are feeling worse.