Transient hepatitis B surface antigenemia in a blood donor after a combination hepatitis A and B vaccine

Transient, confirmed (neutralizable) hepatitis B surface antigenemia following vaccination with monovalent recombinant hepatitis B vaccine is well documented in blood donors, neonates, and hemodialysis patients.1-3 The time frame in blood donors typically is within 3 days after vaccination,1,2 although up to 18 days has been reported.4 Failure to recognize the phenomenon still occurs and has significant ramifications.2,4 A vaccine providing dual protection against hepatitis A and B is now available (Twinrix, SmithKline Beecham, Philadelphia, PA). The standard adult schedule involves three IM injections of 1.0 mL (720 ELISA units of inactivated hepatitis A vaccine and 20 g of recombinant hepatitis B vaccine) at elected date, 1 month later, and 6 months after the first dose, respectively. We report what we believe to be the first case of spurious hepatitis B antigenemia associated with administration of this vaccine. A 21-year-old female Australian Red Cross blood donor who donated blood in July 2002 was ascertained HBsAg-reactive by chemiluminescent immunoassay (ChLIA, PRISM, Abbott Laboratories, Abbott, IL) and EIA and confirmed HBsAg+ by neutralization. Testing for anti-HBc and anti-HBs was negative. The donor had no apparent risk factor for HBV infection and her previous donations in July 2001, February 2002, and May 2002 had screened HBsAg by ChLIA. Two days before the July 2002 donation, as part of a routine course, the donor had been vaccinated with a second dose of Twinrix. The first dose had been administered 29 days before the July 2002 donation. A follow-up blood sample, collected 78 days after the second vaccination, was negative for HBsAg by ChLIA and EIA. In addition, testing for HBV DNA, anti-HBc, HBeAg, and anti-HBe was negative and the ALT was normal. Furthermore, anti-HBs and anti-HAV were detected, consistent with response to the combined vaccine. We concluded that the transient HBsAg positivity in our donor was vaccine-induced and not a true hepatitis B infection. Twinrix vaccination has proven to be highly immunogenic and compares with the serologic responses observed with monovalent hepatitis A and B vaccines;5 however, as with monovalent recombinant hepatitis B vaccine, the presence of HBsAg after Twinrix vaccination should be interpreted with caution. Andrew R. Davis, MD e-mail: adavis@arcbs.redcross.org.au Heather L. Brotchie, MD Bharati A. Mundkur, MD Susan L. Ismay, BSc, MPH Australian Red Cross Blood Service 153 Clarence Street Sydney, NSW 2000, Australia