CDC's Integrated Vaccine Surveillance System: Active surveillance for pandemic influenza preparedness

BACKGROUND

As part of its planning for a potential pandemic influenza outbreak, the CDC piloted the Integrated Vaccine Surveillance System (IVSS) to actively monitor vaccine-associated adverse events. IVSS was tested in 2007 in one metropolitan area in HMO-based clinics conducting annual influenza vaccinations. In 2008, an expanded pilot program was implemented with vaccination clinics conducted by health department in two metropolitan areas. This study reports on 2008 pilot program findings.

METHODS

IVSS allowed vaccinees to self-report mild and severe vaccine reactions through telephone (Integrated Voice Response (IVR)) or a dedicated secure website. Regardless of adverse event status, vaccinees were asked to report daily for 14 consecutive days following vaccination. Information was collected from nonrespondents using Computer Assisted Telephone Interviewing (CATI).

RESULTS

605 vaccinees were recruited into the study, corresponding to an approximate 63% enrollment rate. Ninety percent (n=545) submitted at least one report through IVR, web, or CATI, with a mean of 9 daily reports per participant. Web was the most frequent mode of contact (72% of all contacts), followed by IVR (26%) and CATI (0.2%). Of all participants who reported at least once, 10% reported one or more severe reactions and 61% reported one or more mild reactions.

CONCLUSIONS

The pilot program confirmed vaccinee willingness to self-report adverse events and the importance of offering multiple reporting mechanisms. An expanded pilot program should test the feasibility of integrating IVSS into local health department pandemic preparedness and flu vaccination systems.