Hepatitis B vaccination and adult associated gastrointestinal reactions: a follow-up analysis.

BACKGROUND/AIMS Hepatitis B is the most important infectious cause of acute and chronic liver disease. Hepatitis B vaccine, a highly purified, genetically engineered, single antigen vaccine, has generally been accepted as a safe vaccine. In 2000, the Institute of Medicine noted that few vaccines for any disease have been actively monitored for adverse effects over long periods and encouraged evaluation of active long-term monitoring studies of large populations to further evaluate the relative safety of vaccines. The aim of this study was to accept the charge of the 2000 Institute of Medicine Report and extend our own work to determine the frequency of gastrointestinal adverse reactions after hepatitis B vaccination and determine if this frequency was increased over the background rate of gastrointestinal conditions in the U.S. adult population. METHODOLOGY A retrospective examination of the Vaccine Adverse Events Reporting System (VAERS) database from July 1990 through August 1999 for hepatitis B vaccination and associated gastrointestinal reactions was made. Additionally, as controls, hepatitis A and rubella vaccination associated gastrointestinal adverse reactions reported to the Vaccine Adverse Events Reporting System in adults were analyzed. RESULTS Our analysis shows that the 40-year-old female population between four to eight days after hepatitis B vaccination was at increased risk for developing gastrointestinal reactions. CONCLUSIONS Hepatitis B vaccination was statistically associated by chi 2 analysis with gastrointestinal reactions including: hepatitis, gastrointestinal disease and liver function test abnormalities in comparison to our vaccine control groups. The reaction rate observed is outweighed by the benefits of the vaccine. Further analysis is needed to determine the mechanisms by which hepatitis B vaccine is associated with gastrointestinal reactions.