To the Editor.
—We previously reported1 the results of a randomized trial evaluating the immunogenicity of a DNA-recombinant hepatitis B (HB) vaccine (Recombivax-HB, Merck Sharp & Dohme, West Point, Pa) administered intradermally (ID) at a dose of 2 μg or intramuscularly (IM) at a dose of 10 μg to 80 healthy adults at 0,1, and 6 months. Twelve months after the first vaccination, the number of responders (vaccinees with anti-hepatitis B surface antigen [anti-HBsAg] levels ≥ 10 IU/L) was found to be significantly higher (P<.0001, χ2) in the IM group (36/37, 97%) than in the ID group (21/38, 55%).Six years (mean, 72 months; range, 66 to 78 months) after initiation of vaccination, we obtained serum from 53 (33 women and 20 men; mean age, 36 years; range, 26 to 61 years) of those 68 vaccinees who initially had anti-HBsAg levels greater than 1 IU/L. Twenty subjects
Wiström J. Intramuscular vs Intradermal Hepatitis B Vaccination: A 6-Year Follow-up. JAMA. 1995;273(23):1835-1836. doi:10.1001/jama.1995.03520470043027