Postexposure Prophylaxis for Hepatitis A: What's the Preferred Approach?

Postexposure Prophylaxis for Hepatitis A: What’s the Preferred Approach?

In a head-to-head comparison, hepatitis A vaccine was noninferior to immune globulin.

Both hepatitis A vaccine and immune globulin (IG) have been shown to be effective as postexposure prophylaxis for hepatitis A, but the two strategies have not been directly compared in a randomized, controlled trial. In a blinded, noninferiority trial, researchers in Kazakhstan randomized 1090 nonimmune close contacts (age range, 2–40 years) of persons with hepatitis A to receive one dose of either IG or hepatitis A vaccine within 2 weeks of exposure. The trial was partially funded by the vaccine manufacturer.

Only 4.4% of vaccine recipients and 3.3% of IG recipients developed confirmed symptomatic infection with hepatitis A (relative risk among vaccine recipients, 1.35; 95% confidence interval, 0.7–2.7). Some measures (e.g., degree of jaundice, alanine aminotransferase levels) suggested that disease severity was slightly greater in the vaccine group, but the differences between groups were not statistically significant.

Comment: Hepatitis A vaccine provides excellent postexposure prophylaxis that is only marginally less effective than that provided by IG, but the vaccine provides longer duration of protection and is easier to administer. Further, because IG blunts the response to live vaccines, its administration can lead to a clinically significant delay in the administration of other routine vaccines. Updated recommendations from the CDC Advisory Committee on Immunization Practices state that hepatitis A vaccine is preferred to IG for healthy persons aged 12 months to 40 years, and the AAP now recommends routine administration of hepatitis A vaccine to all children aged 12 to 23 months (see Pediatrics 2007; 120:189 and Journal Watch Infectious Diseases Oct 3 2007). Given the low risk for severe hepatitis A in children, I would use IG only in patients with underlying liver disease for whom the additional 1% difference in efficacy might be clinically significant. As always, preexposure prophylaxis is best.

— Peggy Sue Weintrub, MD

Dr. Weintrub is a member of the speakers’ bureau for Merck and Co., Inc.

Published in Journal Watch Pediatrics and Adolescent Medicine November 28, 2007