IMMUNE-RESPONSE TO INTRAMUSCULAR REVACCINATION AFTER PRIMARY INTRADERMAL VACCINATION AGAINST HEPATITIS-B

We studied the immune response to (re)vaccination with three 1-mL dose s of recombinant hepatitis B vaccine administered intramuscularly on d ays 0, 30, and 180 to 75 public safety workers (PSWs) who had not deve loped antibody to hepatitis B surface antigen (anti-HBs) after three i ntradermal doses of hepatitis B vaccine; to 45 PSWs who had initially developed antibody but did not have detectable levels 11 months after intradermal vaccination; and to 16 hepatitis B-susceptible PSWs. Level s of anti-HBs were measured on days 14 and 210 after the first intramu scular dose. Overall, 46 (61%) of 75 PSWs in the initial-nonresponse g roup, 43 (96%) of 45 PSWs in the lost-response group, and 5 (31%) of 1 6 PSWs in the new-vaccinee group had anti-HBs titers of greater than o r equal to 10 mIU/mL on day 14. On day 210 (after three doses), the fi gures were 62 (89%) of 70 PSWs in the initial-nonresponse group, 43 (9 8%) of 44 PSWs in the lost-response group, and 15 (94%) of 16 PSWs in the new-vaccinee group. We conclude that persons who do not seroconver t after intradermal vaccination should receive three doses of hepatiti s B vaccine by the intramuscular route.