Low-Dose Intradermal Hepatitis B Vaccine

To the Editor.—  In a recent report from the Walter Reed Army Institute of Research, Redfield and colleagues¹ presented the results of a study in which 2 μg of hepatitis B vaccine administered intradermally (ID) to 25 health workers was compared with the standard 20-μg dose administered intramuscularly (IM) to another 25 health workers. Based on similar seroconversion rates and antibody levels achieved, these investigators concluded that the low-dose ID regimen was comparable in immunogenicity with the IM regimen. Obviously, if ID administration requires one-tenth the dose of the IM route, the potential savings in vaccine costs would make this vaccine more affordable and, therefore, more available than it is now. For the military, already under budgetary pressure to limit spending, the dollar savings for a mass vaccination program of military personnel rotating for brief tours of duty through high-risk areas of the world would be substantial.On the