Neutralization positive but apparent false-positive hepatitis B surface antigen in a blood donor following influenza vaccination.

We report a case of transient, confirmed positive hepatitis B surface antigen (HBsAg) in a 25 year old long term Canadian Blood Services (CBS) donor, who reported receiving 2011-2012 seasonal trivalent (A/H1N1, A/H3N2, Influenza B) inactivated influenza vaccine two days before donation. To our knowledge, this report is the first published case implicating influenza vaccine as a possible factor in false-positive HBsAg test results. Seasonal incidence of repeat-reactive HBsAg among CBS donors suggests a potential contributory role of influenza vaccine or community acquired infection. We speculate that influenza vaccine may rarely be associated with sporadic, transient, false-positive HBsAg results.