HABER P, ZHOU W, DESTEFANO F, CHEN RT; VAERS Working Group; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. G-1080.
CDC, Atlanta, GA.
BACKGROUND: An increased risk of Guillain-Barre Syndrome (GBS) was found for swine influenza vaccine in 1976-77. Studies in subsequent years have found relative risks of GBS after influenza vaccination ranging from 1.1 to 2.0. Since 1990, we have been monitoring trends of GBS reports to VAERS, a passive reporting system for vaccine adverse events. METHODS: We selected GBS reports from 7/1/90-4/30/03 following influenza vaccine and calculated reporting rates by influenza season and age-group. Denominator data was obtained from CDC Biologic Surveillance and the National Health Interview Survey coverage data. We performed tests for trend using Poisson regression and z-tests for comparison of rates. In addition, we conducted active follow-up to verify GBS diagnosis and obtain additional clinical details. RESULTS: During the study period, VAERS received 564 GBS reports, for a reporting rate of 0.76 per million doses distributed. For 81% of reports, the GBS diagnosis was verified. The reporting rate was higher in the age-group 18-64 compared to 65 and older; 0.92 vs. 0.68 per million doses distributed (p=0.03). During 1990 to 1996, the reporting rate ranged from 0.78 to 1.66 per million doses. Since the 1996-97 influenza season, we have observed a significant drop in GBS reports, from 1.25 to 0.27 per million doses (p <.001). The median interval between vaccination and onset of GBS has remained essentially unchanged from 13 to 12 days, however. CONCLUSIONS: Monitoring of GBS reports to VAERS after influenza vaccination has detected signals in certain years that have been verified in epidemiologic studies. The recent decrease in GBS reporting rate requires further study to determine if it is an artifact of reporting changes or reflects a true decline in the occurrence of GBS cases after influenza vaccination.
Publication Types:
Keywords:
- Epidemiologic Studies
- Guillain-Barre Syndrome
- Influenza Vaccines
- Influenza, Human
- Vaccination
- Vaccines
- methods
- organization & administration
- trends
Other ID:
UI: 102266459
From Meeting Abstracts