Tracking Vaccine-Safety Inquiries to Detect Signals and Monitor Public Concerns

Abstract

BACKGROUND: The Centers for Disease Control and Prevention frequently receives inquiries from health care providers, public health officials, and the general public seeking data or guidance on vaccine-safety issues. Past inquiries to public health authorities identified potential problems including viscerotropic illness rarely associated with yellow fever vaccination. OBJECTIVE: To systematically describe vaccine-safety inquiries received at the Centers for Disease Control and Prevention. METHODS: External and internal inquiries were recorded in a database from May 1, 2002 to May 31, 2009. Key variables analyzed included the source of the question, the type of information being sought, and the vaccine type(s) associated with the inquiry. RESULTS: A total of 983 vaccine-safety inquiries were answered and analyzed. Health care workers were the source of 43% of the questions, and the general public accounted for 19% of the questions. Nearly half of the requests (49%) concerned information about the Vaccine Adverse Event Reporting System, and nearly one-fourth (21%) were requests from providers for clinical guidance. The most frequent specific topics of inquiry and vaccines involved were neurologic adverse events (AEs) temporally associated with vaccination (17%) and safety of all vaccines or childhood vaccines (20%), respectively. CONCLUSIONS: Questions about rare but potentially serious AEs and general concerns about vaccine safety were encountered relatively frequently. The substantial number of clinically focused inquires may indicate a need for more provider support tools and resources. Tracking of inquiries can supplement information received through vaccine AE reporting and contribute to an enhanced scientific and communications response to vaccine-safety concerns.