According to the Centers for Disease Control and Prevention, an adverse event can be causally attributed to vaccine more readily if one of the following is true.
Is it a vaccine reaction? CDC offers guidance
April 1, 2003
Is it a vaccine reaction? CDC offers guidance
According to the Centers for Disease Control and Prevention, an adverse event can be causally attributed to vaccine more readily if:
- The exact chronology of vaccination and adverse event is known.
- The adverse event corresponds to those previously associated with a particular vaccine.
- The event conforms to a specific clinical syndrome whose association with vaccination has strong biologic plausibility (e.g., anaphylaxis).
- A laboratory result confirms the association (e.g., isolation of vaccine-strain varicella vaccine from skin lesions of a patient with rash).
- The event recurs on re-administration of the vaccine (positive re-challenge).
- A controlled clinical trial or epidemiologic study demonstrates greater risk for a specific adverse event among vaccinated vs. unvaccinated (control) groups.
Source: Iskander JK, Miller ER, Pless RP, et al. Vaccine safety post-marketing surveillance: The Vaccine Adverse Event Reporting System. Atlanta: Centers for Disease Control and Prevention National Immunization Program; 2003.