[Safety and immunogenicity of an anti-hepatitis-B vaccine obtained using the recombinant DNA technique: results of a longitudinal study in hospital personnel]. Long-term follow-up of hepatitis B vaccination in susceptible hospital personnel. Efficacy of heat-inactivated hepatitis B vaccine in haemodialysis patients and staff. Double-blind placebo-controlled trial. Influence of smoking on immunological responses to hepatitis B vaccine. Immune response to hepatitis B vaccine given at different injection sites and by different routes: a controlled randomized study. Low-dose (2 micrograms) hepatitis B vaccination in medical students: comparable immunogenicity for intramuscular and intradermal routes. Comparison of three different schedules of vaccination against hepatitis B in health care workers. Immunogenicity of hepatitis B Vaccines. Implications for persons at occupational risk of hepatitis B virus infection. Immunogenicity of low-dose intradermal recombinant DNA hepatitis B vaccine. Hepatitis B vaccine in medical staff of hemodialysis units: efficacy and subtype cross-protection. A randomized double-blind clinical trial of a mammalian cell-derived recombinant DNA hepatitis B vaccine compared with a plasma-derived vaccine. Intradermal hepatitis B vaccination in a large hospital employee population. Comparison of higher-dose intradermal hepatitis B vaccination to standard intramuscular vaccination of healthcare workers. Hepatitis B vaccine in health care personnel: safety, immunogenicity, and indicators of efficacy. Randomised placebo-controlled trial of hepatitis B surface antigen vaccine in French haemodialysis units: I, Medical staff. Immunogenicity of low-dose intramuscular and intradermal vaccination with recombinant hepatitis B vaccine. Immune response to a new hepatitis B vaccine in healthcare workers who had not responded to standard vaccine: randomised double blind dose-response study. Clinical evaluation of low dose intradermally administered hepatitis B vaccine: a comparison of plasma-derived and recombinant yeast-derived vaccines. Low-cost hepatitis B vaccine improves uptake among self-paying health-care students. Intradermal and intramuscular route for vaccination against hepatitis B. Evaluation of the response to a booster dose of hepatitis B vaccine in previously immunized healthcare workers.
A prospective study of the immunogenicity, safety and persistence of antibodies induced by the DNA-recombinant anti-hepatitis B vaccine Engerix B was conducted in a risk group as health care workers. 115 health care workers were randomly allocated into two groups. Immunization was carried out according to a 0-1-6 month vaccination schedule in one group and to a 0-1-2-12 month schedule in the other group. Results indicate that the DNA-recombinant anti-hepatitis B vaccine is well tolerated and highly immunogenic. Reactogenicity to the vaccine was low in incidence and mild in severity with no significant difference appearing between the study groups. 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. The efficacy of a heat-inactivated hepatitis B vaccine, 3 micrograms of surface antigen (HBsAg), given at 0, 1, 2, and 5 months, was evaluated in 401 haemodialysis patients in 18 centres by a placebo-controlled, double-blind, randomised trial. The attack-rate of hepatitis B virus (HBV) infections in the control group was 18% over 435 days. The protective efficacy rate of the vaccine was 78% against all HBV infections in the entire study (p = 0.00016), and 94% against HBsAg-positive hepatitis more than 3 months after day 0. Those patients in whom HBV developed showed no evidence of vaccine-acquired anti-HBs. Among 152 similarly randomised staff members receiving three monthly injections, all 5 HBsAg-positive infections occurred in the placebo group (p = 0.022). The vaccine induced anti-HBs in 88% of the patients and 100% of the staff. Immediately after the fourth injection, anti-HBs levels were as high in responding patients as in staff. There were no serious side effects. In the four-dose schedule the vaccine provides dialysis patients with protection of the same order as that given by other hepatitis B vaccines to normal subjects. When 115 health-care workers participated in a study that monitored their serological responses to hepatitis B vaccine at regular intervals, it was found that smoking significantly affected their antibody titre responses adversely. The study group was randomly allocated into two comparable groups that received hepatitis B vaccine either in a rapid schedule (vaccination at 0, 1, 2 and 12 months) or a standard schedule-most commonly used worldwide-(vaccination at 0, 1, and 6 months). A significantly higher proportion of smokers, in both schedules, failed to seroconvert and to achieve higher antibody levels at month 3 (p = 0.01) and at month 13 (p = 0.0003). At month 7 a similar pattern was noted in smokers following the standard vaccination schedule (p < or = 0.05), but not in those following the rapid schedule. Two-hundred-ninety-nine hospital workers were randomly allocated to receive MSD hepatitis B vaccine in different injection sites and by different routes (intramuscularly by gluteal or deltoid injections or subcutaneously in the arm) or Pasteur vaccine subcutaneously. Highest rates of seroconversion and highest mean anti-HB, titres were found in subjects given MSD vaccine by intramuscular injection into the deltoid muscle. In a randomized controlled trial, 165 healthy medical students were immunized either by the intramuscular route (IM group) or by the intradermal route (ID group) with low-dose (2 micrograms) plasma hepatitis B vaccine (HB-VAX) at months 0, 1, 2, and 6. At month 7, protective immunity (anti-HBs greater than 10 IU/l) was observed in 90% (95% confidence interval [Cl]: 84-97) of group IM and in 94% (95% Cl: 89-99) of group ID; also geometric mean titres (IM: 533 IU/l; ID:541 IU/l) were very similar at month 7. Sixty-six (IM: 29; ID: 37) of 107 vaccinees with anti-HBs less than 1,000 IU/l at month 7 received a 2 micrograms booster injection at month 12. Long-term immunity (anti-HBs greater than 1,000 IU/l) was finally observed in 58% for group IM and 66% for group ID. For low-dose hepatitis B immunization, which reduces costs to about 16%, the IM route is to be preferred in young healthy individuals in view of an ease of administration, avoidance of long-term local side effects, and the known protective immunity of intramuscularly induced anti-HBs antibodies. Health care workers (HCW) are a group at risk for hepatitis B virus (HBV) infection; as a result, vaccination is recommended. However, elevated cost of the vaccination schedule is one of the limiting factors to this approach. Our aim in this study was to evaluate alternative schedules for vaccination against hepatitis B, in order to obtain safe immunization with reduced costs. We studied 300 HCW, randomized to be submitted to one of three vaccination schedules against hepatitis B: Group A--three doses of 20 micrograms i.m. (n = 103); Group B--first dose i.d. (2 micrograms), second and third doses i.m. (20 micrograms) (n = 97); Group C--first and second doses i.d. (2 micrograms), third dose i.m. (20 micrograms) (n = 100). All individuals received recombinant vaccine at 0, 1 and 6 months. After the first dose, there was no difference among the three schedules, either in terms of anamnestic response or in seroconversion rate. After the second dose, there was statistical difference among the three schedules (A > B > C), in terms of seroconversion rates. After the third dose, seroconversion rates were 92.2% in Group A and 92.8% in group B; geometric mean titers (GMT) in Group B (789.6 UI l-1) were similar to group A (1248.0 UI l-1). Group C presented a seroconversion rate of 78% and a GMT of 323.0 UI l-1, both statistically inferior to other schedules. We concluded that the schedule applied in Group B had similar results when compared to schedule A, with estimated savings of 30% in vaccine costs.(ABSTRACT TRUNCATED AT 250 WORDS) To assess risk factors for decreased immunogenicity among adults vaccinated with hepatitis B vaccine and to determine the importance of differences in immunogenicity between vaccines among health care workers (HCWs).
                Randomized clinical trial and decision analysis.
                HCSw.
                Development of seroprotective levels of antibody to hepatitis B surface antigen (anti-HBs) and the number of expected chronic hepatitis B virus (HBV) infections associated with lack of protection.
                Overall, 88% of HCWs developed seroprotection. Risk factors associated with failure to develop seroprotection included increasing age, obesity, smoking and male gender (P < .05). Presence of a chronic disease was associated with lack of seroprotection only among persons > or = 40 years of age (P < .05). The two vaccines studied differed in their overall seroprotection rates (90% vs. 86%; P < .05), however, this difference was restricted to persons > or = 40 years of age (87% vs. 81%; P < .01). Among HCWs > or = 40 years of age, the decision analysis found 44 (0.34/100,000 person-years) excess chronic HBV infections over the working life of the cohort associated with use of the less immunogenic vaccine compared to the other.
                He patitis B vaccines are highly immunogenic, but have decreased immunogenicity associated with increasing age, obesity, smoking, and male gender; and among older adults, the presence of a chronic disease. One of the two available vaccines is more immunogenic among older adults; however, this finding has little clinical or public health importance. Hepatitis B vaccines should be administered to persons at occupational risk for HBV infection early in their career, preferably while they are still in their training. Low-dose intradermal vaccination with plasma-derived hepatitis B vaccine has been shown to give high rates of seroconversion at greatly reduced vaccine cost. We report a study comparing two groups given lower doses (1.0 or 1.5 microgram) of recombinant-derived vaccine intradermally with a control group given the standard intramuscular dose. Of the 132 randomized medical students and hospital employees, 95 completed the study. Rates of seroconversion and peak antibody titers were comparable, though antibody rose more slowly and fell somewhat faster in the intradermal groups. Increasing the intradermal dose did not improve response. Most intradermal vaccinees (80%) developed small (average 2 to 3 mm) areas of local induration, which faded slowly. Low-dose intradermal vaccination with recombinant hepatitis B vaccine results in high rates of seroconversion (greater than 90% in each protocol) at a cost that will allow individual practitioners and program with limited budgets to offer vaccination. We evaluated the efficacy of hepatitis B vaccine (Heptavax-B) containing only the ad subtype in a randomized, placebo-controlled, double-blind trial among 865 staff members of 43 hemodialysis units in the United States. Surface antibody developed in 92.6 per cent of the subjects after two doses of vaccine and in 96 per cent after the six-month booster. The incidence of infections with hepatitis B virus (with or without hepatitis) was 9.9 per cent in placebo recipients and 2.2 per cent in vaccine recipients (P less than 0.01). The two cases of hepatitis B among vaccine recipients did not occur in subjects in whom antibody had developed. In 81 per cent of the hepatitis events, the virus was of the ay subtype. The indicence of ay virus was 8.2 per cent among placebo recipients and 1.2 per cent among vaccine recipients (P less than 0.005). We conclude that these data confirm the efficacy of the vaccine and demonstrate subtype cross-protection. Eight hundred volunteers from heath care and emergency fields participated in a randomized double-blind clinical trial of a new experimental mammalian cell-derived recombinant DNA hepatitis B vaccine (Betagen) compared with a licensed plasma-derived vaccine (Heptavax-B). Vaccine injections (20 micrograms) were administered intramuscularly at 0, 1, and 6 months, and sera were tested at 0, 1, 2, 3, 6, 7, and 12 months for hepatitis B surface antigen, antibody to hepatitis B surface antigen, and antibody to hepatitis B core antigen. Data from 745 vaccinees (93.1%), analyzed at the 7th month of follow-up, showed no significant difference in the seroconversion rates for Betagen (94.4%) vs Heptavax-B (97.3%), but the geometric mean titer of antibody was significantly higher for Heptavax-B (11 833 mIU/L) than for Betagen (4628 mIU/mL). The antibody response of Betagen was significantly and independently related to age and sex, while that of Heptavax-B was related to age only. Reported side effects from both vaccines were minor and mild, with approximately one fourth of all vaccinees reporting at least one side effect. Vaccinees, who had a protective level of antibody at the 7th month, were tested for antibodies at the 12th month. Of those in the Betagen-vaccinated group and those in the Heptavax-B-vaccinated group, 99.0% and 100%, respectively, were still protected. There was a proportionately larger decline in the geometric mean titers of antibody to hepatitis B surface antigen for Heptavax-B than for Betagen. The intradermal route of hepatitis B vaccine administration has been tested in several clinical trials and has produced various degrees of immunogenicity, but usually among small groups of participants. To assess more adequately the immunogenicity of hepatitis B vaccine using the intradermal route, the Centers for Disease Control conducted a clinical trial among 425 well health-care workers in a hospital setting. Participants were randomly assigned to one of two treatment groups: those receiving a 20 micrograms intramuscular injection, and those receiving a 2 micrograms intradermal injection. Participants received the plasma-derived hepatitis B vaccine by the standard schedule at 0, 1 and 6 months, and serum samples were collected at 3, 8, 12 and 24 months after the first dose. Antibody response rates (anti-HBs titre greater than or equal to 10 sample ratio units by radioimmunoassay) for the intradermal vaccination group were consistently lower than those for the intramuscular vaccination group at each testing interval. The differences were greatest for the 3-month test and decreased over time. Geometric mean titres for anti-HBs for the intradermal group were significantly lower than those for the intramuscular group at the 8-month test point. In addition to inoculation route, factors of gender, smoking and age were found to have significant effects on immune response. The results suggest that intradermal vaccination with hepatitis B vaccine may be appropriate under certain conditions and for certain population subgroups. To compare the immunogenicity of hepatitis B vaccine administered via intradermal (ID) versus intramuscular (IM) route.
                Subjects chose either to specify the route of immunization or to undergo random allocation to vaccination by the ID (0.15 mL) or the IM (1.0 mL) route. Yeast-derived recombinant hepatitis B vaccine was given at 0, 30, and 180 days. Hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb) were measured by microparticle enzyme immunoassay.
                763 subjects were enrolled. Baseline screening identified 65 subjects (8%) who were positive for HBsAb or HBcAb. Vaccination was completed by 590 (85%) of 698 enrollees (370 ID, 220 IM). Seroconversion rates (geometric mean titers [GMT]>0 IU/mL HBsAb) for those vaccinated ID were 99% and 96% for screening at 9 months and 1 year post-vaccination, respectively; subjects vaccinated intramuscularly had similar rates of 95% and 96%. Seropositivity rates (GMT > or = 10 IU/mL HBsAb) showed a similar pattern, with 95%, 92%, and 73% at 9 months and 1 and 2 years, respectively, for those vaccinated ID, and 94%, 93%, and 81% for those having IM vaccination. GMT for HBsAb was significantly higher for individuals vaccinated IM than for those vaccinated ID (P<.0001). The GMT ratio for the IM and ID routes decreased over time, being 9.3 at 9 months, 7.8 at 1 year, and 5.9 at 2 years. An unanticipated side effect of intradermal vaccination was skin discoloration at injection sites, which persisted for at least 2 years postvaccination. Two thirds (112/166) of respondents reported that they would have selected the ID route despite the discoloration.
                Higher-dose ID vaccination (3 vs 1 microg per injection) uses one sixth of the dose required for standard IM vaccination. It is a cost-effective way to vaccinate populations against hepatitis B virus, but the long-term efficacy of the ID route must still be investigated. In a double-blind trial, we randomly assigned 1330 high-risk health care personnel to receive three 20-micrograms doses of hepatitis B vaccine or placebo. Among vaccine recipients 58% responded within 1 month and 97% within 9 months; there was no difference in immune response to the vaccine between men and women. Efficacy was evaluated after a mean follow-up of only 13.2 months, just before the vaccine was released commercially. Five hepatitis B infections were identified in placebo recipients and one in a vaccine recipient. Although the number of infections was too small to allow confident conclusions about protective efficacy of the vaccine, we saw a 67% reduction in the need for hepatitis B immune globulin after accidental hepatitis B inoculation in the vaccine group (relative risk, 5.08; 95% confidence intervals, 1.3 to 19.9). Minor side effects occurred with equal frequency after vaccine (28.7%) and placebo (27.2%) injections; no participant had a severe adverse reaction. Vaccination with the 20-micrograms hepatitis B vaccine was highly immunogenic and safe in health care workers. A vaccine against hepatitis B surface antigen (Institut Pasteur Production) was assessed in staff members from forty-eight French haemodialysis units where the risk of hepatitis B was high. Of 318 subjects who completed the protocol, 164 received three monthly injections of vaccine and 154 received corresponding injections of placebo. Hepatitis B infection was observed in 3.6% of the vaccine group and 12.3% of the placebo group (p less than 0.005). The 6 infections in the vaccine group all arose within 63 days from the first injections, whereas the 19 in the placebo group arose throughout the 12 months of follow-up. The rate of side-effects after injection did not differ in the two groups. 94% of the vaccine recipients had an immune response ( greater than 10 mIU/ml in at least 5 successive specimens). 4 months after the first injection the mean + or - 2 SE peak level of anti-HBs was 2433 + or - 1077 mIU/ml. The study is a randomized trial using recombinant DNA vaccine to determine whether an intramuscular 10 micrograms dose or intradermal 2 micrograms induces satisfactory anti-HBs levels compared to the standard dose of intramuscular 20 micrograms. Participants were 359 healthy medical and nurse students randomly allocated to one of the three groups: Group I-IM 20 micrograms; Group II-IM 10 micrograms; Group III-ID 2 micrograms at 0, 1 and 6 months. Anti-HBs titres were measured after complete vaccine schedule by ELISA/Pasteur. Baseline variables were similar among groups and side effects were mild after any dose. Vaccines in the IM-10 micrograms group had seroconversion rate and geometric mean titre (GMT 2344 IU L-1), not significant different from the IM-20 micrograms group (GMT 4570 IU L-1). On the contrary, 21.4% of the ID-2 micrograms recipients mount antibody concentration below 10 IU L-1 and GMT of 91 IU L-1, a statistically significant difference compared with the standard schedule IM-20 micrograms (p < 0.001). A three dose regimen of half dose IM could be considered an appropriate schedule to prevent hepatitis B in young health adults which is of relevance to the expansion of hepatitis B vaccine programme. To evaluate the immunogenicity and reactogenicity of a new triple S recombinant hepatitis B vaccine in a cohort of healthy people in whom currently licensed hepatitis B vaccines had persistently not induced an immune response.
                Single centre, randomised, double blind, dose-response study.
                Research vaccine evaluation centre at a teaching hospital.
                100 healthcare workers aged 18-70 years with a history of failure to seroconvert after at least four doses of a licensed hepatitis B vaccine containing the S component.
                Each subject was randomly allocated two doses of 5, 10, 20, or 40 micrograms of a new hepatitis B vaccine two months apart.
                Immunogenicity of the four doses. Seroconversion and seroprotection were defined as an antibody tire > 10 IU/l and > 100 IU/l respectively against an international antibody standard.
                69 subjects seroconverted after a single dose of the vaccine. After the booster vaccination one other subject seroconverted, bringing the overall seroconversion rate to 70%. Fifteen subjects given 5 micrograms of vaccine, 19 given 10 micrograms, 16 given 20 micrograms, and 20 given 40 micrograms seroconverted. Seroconversion rates in the four antigen dose groups were 60% (15/25), 76% (19/25), 64% (16/25), and 80% (20/25). After the booster dose there was no significant dose-response effect on the overall seroconversion rate, although the small sample size meant that a clinically important dose-response could not be ruled out.
                A single dose of 20 micrograms of the vaccine was as effective as two doses of either 40 micrograms or 20 micrograms of this vaccine formulation in terms of seroconversion, seroprotection, and geometric mean titres. A study of the safety and immunogenicity of plasma-derived and yeast-derived recombinant hepatitis B vaccines administered by the intradermal route is reported. Three groups of medical students were inoculated intradermally at 0, 1 and 6 months with 2 micrograms of vaccine. Group 1 (n = 24) were administered plasma-derived vaccine (Green Cross HB-vaccine), group 2 (n = 21) yeast-derived recombinant vaccine (Engerix B), and group 3 (n = 13) two doses of plasma-derived vaccine with a third dose of yeast-derived vaccine. One month after administration of the third dose of vaccine, seroconversion rates in each of the three groups were 83, 100 and 92%, respectively, with anti-HBs geometric mean titres (GMT) of 329 IU l-1, 1390 IU l-1 and 1061 IU l-1. Although differences in seroconversion rates were not statistically significant, the GMT in group 1 was significantly lower than that in group 2 (p less than 0.01) and group 3 (p less than 0.05). The results presented show that intradermal administration of plasma-derived or yeast-derived vaccine, or a combination of the two, can provoke an effective immunogenic response to hepatitis B virus at approximately 10% of the cost of intramuscular vaccination. In this study administration of yeast-derived vaccine yielded better results than plasma-derived vaccine when administered by the intradermal route. Advisory committees recommend hepatitis B (HBV) immunization for professional and student health-care workers. However, the currently licensed vaccines are expensive, and previous surveys have shown that few students (14%) have been immunized in Canada. A low-cost immunization program was offered to health-care students in order to determine whether the effectiveness of HBV immunization could be improved by substantially reducing the vaccine cost to recipients. The immunogenicity, side effects, and 3-dose completion rate of a low-cost Korean HBV vaccine were compared with a similar U.S.-made vaccine. A total of 922 postsecondary students enrolled in 6 health-care disciplines in Ottawa, Canada were surveyed for hepatitis-B immunization status. Nonimmunized students were subsequently offered HBV vaccine at total cost of $15 (Canadian), randomly allocated to receive 3 intramuscular doses of either Korean or U.S.-made plasma-derived HBV vaccine in a double-blind fashion, surveyed about side effects, and tested for hepatitis B surface antibody seroconversion. Only 12% of the 922 surveyed students had been previously immunized when vaccine was obtainable only at high cost. However, 66% of those not immunized participated in the vaccine trial and paid the $15 fee. Hepatitis-B surface antibody seroconversion (greater than or equal to 10 sample ratio units by radioimmunoassay) occurred in 291/311 (93.6%) and 299/310 (96.5%) of recipients of 3 doses of the Korean and U.S. vaccines, respectively (P = 0.10). There were no meaningful differences in vaccine adverse effects, and 92.6% of recipients of either vaccine completed 3 doses.(ABSTRACT TRUNCATED AT 250 WORDS) 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. Hepatitis B vaccination is recommended for all healthcare workers (HCW) at risk of exposure to infectious body fluids. However, the absolute duration of protection from immunization is unknown. The purpose of this randomized comparison trial was to determine how previously immunized HCW respond to different booster doses of hepatitis B vaccine.
                Adult HCW (n=59) were classified by level of hepatitis B surface antigen (anti-HBs), either <10 milli-International Units per milliliter (mIU/ml) or 10-50 mIU/ml. Participants were then randomized to receive a 2.5 or 10 microg dose of hepatitis B vaccine. Evaluation of anti-HBs levels were conducted 10 to 14 days, one month and one year postbooster.
                All participants responded to the booster dose with increased anti-HBs levels. At 14 days, mean anti-HBs levels were significantly higher for those with higher levels at baseline (P=0.004) and those receiving the 10 microg dose (P=0.016). At one month, those with higher anti-HBs levels at baseline and those receiving the 10 microg dose were significantly higher (P<0.01 for both). At one year, the increase for the higher dose was no longer statistically significant when examined by itself (P=0.081); statistical significance (P=0.021) was achieved after adjusting for anti-HBs level at baseline. For all participants, the geometric mean anti-HBs level was 2618 mIU/ml at 14 days, 2175 mIU/ml at one month and 88.9 mIU/ml at one year. At all time points the increase in anti-HBs levels represented an increase over the geometric mean baseline level of anti-HBs (7.4 mIU/ml). Hepatitis B immunized adults responded to a booster dose of hepatitis B vaccine from 3 to 13 yr postvaccination series. Data support current recommendations that immunized HCW do not require periodic antibody testing or vaccine boosters.
PDV significantly prevents hepatitis B events. RV seems to be able to elicit similar protective anti-HBs levels. The intramuscular route with 20 µg RV was significantly more effective compared with the intradermal route with 2 µg RV as was the standard schedule compared with a rapid schedule and deltoid intramuscular injection compared with the gluteal intramuscular injection. It is unclear if booster vaccination of non-responders offers higher anti-HBs seroconversion and hepatitis B vaccine prevents the infection of hepatitis B mutants in health-care workers.