Fatal Syncope-Related Fall After Immunization

A 15-year-old boy with no known medical problems experienced vasovagal syncope several minutes after the third dose of hepatitis B vaccine. He fell backwards onto a concrete floor covered by a thin carpet, striking his occiput, and was momentarily unconscious. He briefly regained consciousness and complained of pain in the chest and arms. Then he reportedly had convulsions and went into cardiopulmonary arrest. Resuscitation attempts were unsuccessful. In a nearby emergency department, he was found to be in ventricular fibrillation, and attempts at defibrillation were unsuccessful. Autopsy revealed frontal lobe contusions, cerebral hemorrhage, cerebral edema, and no skull fracture. The death was ruled as accidental, and the medical examiner concluded that a vasovagal reaction had led to this injury. This death was first reported in the lay press, and then the events were reported to the Vaccine Adverse Event Reporting System (VAERS). The Food and Drug Administration (FDA) has previously described reports of syncope and unintentional injury after immunization,¹ and there are now recommendations^{2 - 3} that patients be observed for 15 to 20 minutes after immunization.

Since the first of these recommendations was published in June of 2000,² the FDA has received approximately 107 reports of syncope/presyncope and unintentional injury on the day of vaccination. Most (100) of these injuries reportedly occurred within 20 minutes of vaccination. One hundred five reports described falls, and 2 motor vehicle collisions were reported, including 1 that occurred 10 to 15 minutes after vaccination. Most (83) of the vaccinees were between 2 and 17 years old. Three reports described a history of syncope (with or without injury) after a previous vaccination.

In addition to the fatal event described above, 2 other syncope reports described severe head injuries. A 21-year-old man experienced intracerebral bleeding after falling backwards onto the floor 3 minutes after hepatitis B vaccine, tetanus toxoid, and diphtheria vaccine. He reportedly recovered without sequelae. An 18-year-old woman was in a fatal motor vehicle collision after she “passed out while driving her car” approximately 7 hours after meningococcal polysaccharide vaccine; the 7-hour interval between vaccination and the collision makes vaccine-related vasovagal syncope unlikely.

Sixty-five reports described moderate or minor injuries, most commonly contusions and lacerations of the head and extremities. Treatment included sutures, analgesics, and observation. The remaining reports (n=39) described falls without any fractures, contusions, or lacerations. Treatment was limited to observation and placement in a lying or sitting position.

At the time of the reported injury, nearly all (96) of these vaccinees were still in the clinic or other vaccination setting; 3 others were in the clinic parking lot. Although the vast majority of the reports of unintentional injury after vaccination do not describe any permanent sequelae, the continued occurrence of injuries and their potential preventability emphasize the need for vigilance in the immediate postvaccination period, with attention to the current recommendations.

Correspondence: Dr Woo, Center for Biologics Evaluation and Research, Food and Drug Administration, HFM-222, 1401 Rockville Pike, Rockville, MD 20852 (wooj@cber.fda.gov).