Clinical Health Updates

Hep A vaccine similar to immune globulin for postexposure prophylaxis

Clinical Question:
Is the hepatitis A vaccine an alternative to immune globulin for postexposure prophylaxis?

Bottom Line:
Hepatitis A is a reasonable alternative to immune globulin. Advantages of the vaccine include the likelihood of subsequent immunity, the fact that it is not a blood product, a less painful injection, and its wider availability, while a disadvantage is higher cost (although the authors argue that the cost of immune globulin is nearly as high as that of vaccine now).

Reference:
Victor JC, Monto AS, Surdina TY, et al. Hepatitis A vaccine versus immune globulin for postexposure prophylaxis. N Engl J Med 2007;357(17):1685-1694.

Study Design:
Randomized controlled trial (double-blinded)

Synopsis:
Hepatitis A vaccine administered to persons after exposure to the hepatitis A virus has not been compared directly with immune globulin, which is known to be highly effective in preventing hepatitis A when given within 2 weeks after exposure to the virus. They randomly assigned household and day-care contacts, 2 to 40 years of age, in Almaty, Kazakhstan, to receive one standard age-appropriate dose of hepatitis A vaccine or immune globulin within 14 days after exposure to patients with hepatitis A. Instances of laboratory-confirmed, symptomatic hepatitis A infection occurring between 15 and 56 days after exposure were then assessed during active follow-up of all susceptible contacts. Of 4524 contacts who underwent randomization, 1414 (31%) were susceptible to hepatitis A virus and 1090 were eligible for the per-protocol analysis. Among these contacts, 568 received hepatitis A vaccine and 522 received immune globulin. Most contacts were children (average age, 12 years), and most received prophylaxis during the second week after exposure (average interval after exposure, 10 days). The baseline characteristics of the contacts were similar in the two groups. Symptomatic infection with hepatitis A virus was confirmed in 25 contacts receiving vaccine (4.4%) and in 17 contacts receiving immune globulin (3.3%) (relative risk, 1.35; 95% confidence interval, 0.70 to 2.67).