RESUMO
BACKGROUND: Korea is a highly prevalent area of isolated anti-HBc with a rate of 15%, but there is neither vaccination nor management guideline agreed. To know the management for Hepatitis B Vaccination for adults with isolated anti-HBc, we investigated immune response to hepatitis B vaccination in adults with isolated anti-HBc. METHODS: The 23 adults with persistent isolated anti-HBc, who visited a health promotion center from Dec. 1998 to Aug. 1999, were vaccinated with Hepavax?-B by the standard schedule (0, 1, 6 month) and anti-HBs titers were measured 1 month after 1st and 3rd vaccinations (1, 7 month). RESULTS: After the 1st vaccination, 18 (78.26%) developed anti-HBs seroconversion. Among them, 4 (17.39%) had titers of 10~49 mIU/ml, 8 (34.78%) 50~99 mIU/ml, and 6 (26.09%) more than 100 mIU/ml. All non-responders after the 1st vaccination remained as such even with 3 doses of complete vaccination. The majority of seroconverted group did not show more anti-HBs response with further vaccination. CONCLUSIONS: Since none of adults with isolated anti-HBc had a primary response, which indicated few false positive results. Therefore they should be excluded on vaccination programs in Korea. To differentiate between immunity and occult infections, a single dose of vaccine with a follow-up anti-HBs test is preferable for adults with isolated anti-HBc. If the test shows a seroconversion it would indicate protective immunity, if not, then occult infection may be suspected.