Journal of Vaccines & Vaccination

Abstract

Bell’s Palsy Cases Following Administration of Influenza A (H1N1) 2009 Monovalent Vaccine Reported to the Vaccine Adverse Event Reporting System (VAERS)

Maria Cano, Paige Lewis, Alan C. Ou, Devindra Sharma, Claudia Vellozzi and Karen R Broder

Background: With the introduction of 2009-H1N1 vaccine in July 2009, Bell’s palsy was one of the adverse events monitored through an enhanced Vaccine Adverse Event Reporting System (VAERS) surveillance during 2009-2010 influenza season. Methods: We retrospectively reviewed reports to VAERS and available medical records of persons vaccinated with 2009-H1N1 and 2009-2010 seasonal influenza vaccines during July 1– November 30, 2009. We assessed the demographic and clinical characteristics of Bell’s palsy patients and the reporting rates of Bell’s palsy following these vaccinations. Results: We verified 65 cases Bell’s palsy after 2009-H1N1 vaccination and 31 cases after seasonal influenza vaccination. Characteristics of Bell’s palsy cases after 2009-H1N1 vaccination were comparable to those after seasonal influenza vaccination and those previously described for Bell’s palsy. The overall reporting rate was 2.6 times higher after 2009-H1N1 vaccination than seasonal influenza vaccination but substantially lower than background incidence rates. Conclusion: There was no pattern in the demographic and clinical characteristics to suggest an increased risk of Bell’s palsy after 2009-H1N1 vaccination. The higher reporting rate of Bell’s palsy to VAERS following receipt of 2009-H1N1 vaccine compared to seasonal influenza vaccine may be due to stimulated reporting.