Hepatitis B vaccination in healthy Chinese adults with low dose regimens

Hepatitis B vaccination alone is not adequate for the categorizing of adult subjects with isolated anti-HBc

To evaluate the meaning of isolated antibody to hepatitis B core antigen (anti-HBc), 88 Chinese subjects with isolated anti-HBc received rescreening of hepatitis B virus (HBV) markers. Eighty (90.9%) of them were still positive for this antibody and 29 were also found to be positive for antibody to hepatitis B surface antigen (anti-HBs). The remaining 51 subjects (58.0%) were positive for anti-HBc alone; 50 of them received a four-dose schedule of hepatitis B (HB) vaccine. After the initial dose, only one vaccinee disclosed an amnestic anti-HBs response, that is, anti-HBs titre > 1000 miu/mL. Forty-five vaccinees completed the vaccination schedule and 44 (97.8%) had anti-HBs response. The anti-HBs responses in 25 of these vaccinees were compared with 25 age- and sex-matched normal susceptible vaccinees. The anti-HBs response rates in both groups were the same (96 vs 96%). However, the geometric mean titre was significantly lower in the vaccinees with isolated anti-HBc (512 mIU/mL vs 4688 mIU/mL, P < 0.001). Prevaccinated sera were available in 49 vaccinees with isolated anti-HBc for detection of antibody to hepatitis B e antigen (anti-HBe) and HBV DNA; 37 (75.5%) of them had one or two of these markers. As we regarded the rescreening of HBV markers, response to hepatitis B vaccination and presence or absence of anti-HBe and/or HBV DNA together for categorizing the 88 subjects with isolated anti-HBc, at least three-quarters of them had past infection of HBV. The subjects with false positive anti-HBc test were a minor group.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up of hepatitis B vaccination in susceptible hospital personnel

Two hundred and sixty-seven susceptible hospital personnel who had been randomly divided into three groups to receive different doses (5 micrograms, 2 micrograms or 1 microgram) of a plasma-derived hepatitis B vaccine on a four-dose schedule were investigated annually for 4 years. Of them, 251 were vaccine responders. The percentages of persistence of antibody to hepatitis B surface antigen (anti-HBs) in these 3 groups were 95.5% (84/88), 92.3% (72/78) and 95.3% (81/85), respectively (P greater than 0.05). During the follow-up period, 12 of 21 (57.1%) responders with low anti-HBs titres (10-100 miu/mL) and 3 of 48 (6.3%) responders with medium anti-HBs titres (101-1000 miu/mL) were found to be anti-HBs seronegative, while none of the 182 candidates with high anti-HBs levels (greater than 1000 miu/mL) lost their anti-HBs. The 4 year cumulative rate of natural booster in the responders was 11.6% (29/251). None of the candidates became HBsAg positive during the follow-up period. This study revealed that low dose hepatitis B vaccine can provide satisfactory immunogenic response and long-term efficacy in Chinese adults and that the persistence of immunogenicity is not related to the vaccine dose but to the candidate's own initial anti-HBs response.

Booster response to recombinant yeast-derived hepatitis B vaccine in vaccinees whose anti-HBs responses were initially elicited by a plasma-derived vaccine

One hundred and eight primary school students who had been vaccinated with three doses of a plasma-derived hepatitis B vaccine were randomly divided into two groups, to receive a booster dose of either the same vaccine or of a recombinant yeast-derived vaccine. The pre-booster anti-hepatitis B surface antigen (HBs) geometric mean titres (GMT) were similar in both groups (281.8 mIU ml-1 versus 295.1 mIU ml-1, p greater than 0.5). One month after booster vaccination, all the vaccinees in both groups had a marked elevation in their anti-HBs titres, the anti-HBs GMT in group 1 and group 2 being 19,952.6 and 51,286.1 mIU ml-1 (p less than 0.05), respectively. In conclusion, the recombinant yeast-derived hepatitis B vaccine was able to elicit an excellent booster response in vaccinees who had originally received a plasma-derived vaccine.

Intradermal and intramuscular route for vaccination against hepatitis B

A recombinant hepatitis B vaccine was administered to high-risk hospital personnel by intramuscular (20 micrograms) or intradermal (2 micrograms) injections for the primary immunization (n = 69) with three doses and booster immunization (n = 51) with one dose. Basic vaccination performed intramuscularly gave rise to significantly higher seroconversion levels (97.2% versus 78.1%) and geometric mean titres of antibody (1649 versus 126 IUl-1) as compared with the intradermal route. Intradermal administration did not boost antibody titres in patients previously vaccinated intradermally. Adverse reactions were not serious or severe. The intramuscular route is recommended as the procedure of choice when vaccinating against hepatitis B.

Long-term immunogenicity and efficacy of hepatitis B vaccine in infants born to HBeAg-positive HBsAg-carrier mothers

In an attempt to evaluate the long-term immunogenicity and efficacy of plasma-derived hepatitis B vaccine in preventing hepatitis B virus infection, 199 infants born to hepatitis B e antigen-positive hepatitis B surface antigen-carrier mothers were found to be antibody to HBsAg-positive (greater than or equal to 10 mIU per ml) 2 months after the first booster of hepatitis B vaccination at age 1, and their serum HBsAg and anti-HBs were rechecked annually to ages 3 to 5. Of the nine infants whose initial anti-HBs were low (10 to 100 mIU per ml) in concentration, four (44%) were found to be anti-HBs seronegative at age 3, while none of the 127 vaccine responders with high anti-HBs levels (greater than 1,000 mIU per ml) lost their anti-HBs during the 4-year follow-up period. Also, in 63 infants whose initial anti-HBs titers were around 101 to 1,000 mIU per ml, only two lost their anti-HBs at age 4, and another two at age 5, respectively. Whether the vaccine responders lost their anti-HBs or not, no hepatitis B virus infection occurred in these vaccinees during the follow-up period. Thus, in the first 5 years of life, the protective efficacy in the high-risk infants who responded to plasma-derived hepatitis B vaccine was 100%. Because of the diversity of anti-HBs response in individuals, we suggest testing anti-HBs titer in all vaccinated infants after the first booster vaccination in order to calculate the time of next booster before the minimal protective level is reached.