Post-Vaccination Paresthesia: Evaluation of Reports to the Vaccine Adverse Event Reporting System (VAERS)

Background: Post-vaccination paresthesia is a common adverse event and was included as a priority topic in the Vaccine Analytic Unit’s (VAU) anthrax vaccine safety research agenda.

Objectives: Paresthesia is one of the most common vaccine adverse events reported to the Vaccine Adverse Event Reporting System (VAERS).  To better understand the context in which this adverse event is reported, we evaluated reports of paresthesia to VAERS.

Methods: We performed an automated search for all primary, U.S. reports to VAERS received through December 18, 2008 for individuals aged 17-65 coded as the Medical Dictionary for Regulatory Activities (MedDRA®) preferred term “paresthesia.”  The published criteria of number of cases (n) ≥ 3, proportional reporting rate ratio (PRR) ≥ 2, and chi-square ≥ 4 were used to detect disproportionate reporting (i.e., elevated proportional reporting compared to rates for other vaccines) for each vaccine with this MedDRA® preferred term.

Results: Of a total of 86,328 primary, domestic VAERS reports for individuals age 17-65, 4,216 (4.9%) had the MedDRA® preferred term for paresthesia.  Paresthesia was the 19^th most common (out of approximately 2,200) adverse event reported in this group.  Paresthesia was reported in association with 39 different vaccines.  Disproportionate reporting was not observed for any vaccine.  Furthermore, the majority of individuals also had MedDRA® codes for acute or chronic conditions known to be associated with the symptom paresthesia.

Conclusions: We found no disproportionate reporting in VAERS for paresthesia after any vaccine.  Furthermore, we found the symptom paresthesia to be nonspecific and, in the majority of cases, reported in the context of a distinct paresthesia-related medical condition.  Should signals for paresthesia arise in future vaccine safety surveillance, efforts should be made to identify specific paresthesia-related conditions that may be responsible for the increased reporting rates.  Follow-up investigations should focus on those specific conditions of concern.