Adverse Events Following Tetanus Toxoid-Containing Vaccines

Documented Evidence of Dizziness and Syncope

The Centers for Disease Control and Prevention recommends monitoring patients for approximately 15 minutes after vaccination to prevent fall-related injuries from syncope, which has been reported in 6 adolescent recipients of Tdap vaccine, with all incidents resolving without sequelae 1
The FDA drug label for tetanus toxoid-containing vaccines lists dizziness and syncope as postmarketing adverse events, with a warning that procedures should be in place to avoid injury from fainting, particularly in adolescents and young adults 1

Vasovagal reactions, including dizziness and syncope, are typically self-limited and occur immediately after vaccination, representing a physiologic response to the injection procedure itself rather than a direct toxic effect of the vaccine, with a critical timing of within 30 minutes suggesting vasovagal syncope 1

The Centers for Disease Control and Prevention distinguishes between dizziness and syncope, which are documented adverse events, and serious neurologic complications like Guillain-Barré syndrome, peripheral neuropathy, or encephalopathy, which are exceedingly rare, with the FDA considering a history of Guillain-Barré syndrome within 6 weeks of a previous tetanus toxoid-containing vaccine as a precaution for subsequent doses 2

A single episode of vasovagal syncope or dizziness does not preclude future tetanus toxoid-containing vaccines, as these are self-limited reactions rather than true contraindications, according to the American Academy of Pediatrics 1